omniomni/omni-engineering huggingface dataset:
Ashdown Engineering. Ashdown Engineering is a British manufacturer of instrument amplifiers, particularly for bass and acoustic guitars.

History
The company was founded in 1997 by Mark Gooday, a chief engineer and managing director at Trace Elliot. When Gooday was let go by Trace Elliot's then parent company, Kaman, and prior to Kaman closing the doors to the UK distribution and factory facilities, he had been planning to start his own company. The company was named 'Ashdown' after Gooday's wife's family name, and the logo was constructed from this, his passion for cars and the Austin-Healey motor badge.

Besides bass amplifiers and cabinets, the company makes effect pedals for bass players.

Initially focusing on bass guitarists, in 2001 the company introduced a line of guitar amplifiers (50W and 100W stacks and combos) called Peacemaker. Later, more affordable models in 20W and 40W were added, with cheaper PCB technology.

Ashdown have gone on to produce hand-wired amplifiers, and set up a separate company for this, called Hayden.

References

External links 

Mark Gooday Interview at NAMM Oral History Collection (2017)

Guitar amplifier manufacturers
Audio equipment manufacturers of the United Kingdom
Companies established in 1997
Companies based in Essex
Ferrochrome. Ferrochrome or ferrochromium (FeCr) is a type of ferroalloy, that is, an alloy of chromium and iron, generally containing 50 to 70% chromium by weight.

Ferrochrome is produced by electric arc carbothermic reduction of chromite. Most of the global output is produced in South Africa, Kazakhstan and India, which have large domestic chromite resources. Increasing amounts are coming from Russia and China. Production of steel, especially that of stainless steel with chromium content of 10 to 20%, is the largest consumer and the main application of ferrochrome.

Usage
Over 80% of the world's ferrochrome is utilised in the production of stainless steel. In 2006, 28,000,000 tons of stainless steel were produced.
Stainless steel depends on chromium for its appearance and resistance to corrosion. Average chrome content in stainless steel is approx. 18%. It is also used to add chromium to carbon steel. FeCr from South Africa, known as "charge chrome" and produced from a Cr containing ore with a low carbon content, is most commonly used in stainless steel production. Alternatively, high carbon FeCr produced from high-grade ore found in Kazakhstan (among other places) is more commonly used in specialist applications such as engineering steels where a high Cr/Fe ratio and minimum levels of other elements (sulfur, phosphorus, titanium etc.) are important and production of finished metals takes place in small electric arc furnaces compared to large scale blast furnaces. In the past, Ferrochrome alloys were used in the formulation of Type III Compact Cassettes.

Production

Ferrochrome production is essentially a carbothermic reduction operation taking place at high temperatures. Chromite (an oxide of Cr and Fe) is reduced by coal and coke to form the iron-chromium alloy. The heat for this reaction can come from several forms, but typically from the electric arc formed between the tips of electrodes in the bottom of the furnace and the furnace hearth. This arc creates temperatures of about . In the process of smelting, huge amounts of electricity are consumed, making production very expensive in countries where power costs are high.

Tapping of the material from the furnace takes place intermittently. When enough smelted ferrochrome has accumulated in the furnace hearth, the tap hole is drilled open and a stream of molten metal and slag rushes down a trough into a chill or ladle. Ferrochrome solidifies in large castings which are crushed for sale or further processed.

Ferrochrome is generally classified by the amount of carbon and chrome it contains. The vast majority of FeCr produced is "charge chrome" from South Africa, with high carbon being the second largest segment followed by the smaller sectors of low carbon and intermediate carbon material.

Trading
In March 2021, the Shanghai Futures Exchange decided that it would list ferrochrome futures at some unknown date. At the time, ferrochrome spot 6–8% C, basis 50% Cr, ddp China was trading at $1,336–1,382. In January 2021 the spot price had been 25% lower.

References

Chromium alloys
Ferroalloys
SSN-21 Seawolf. SSN-21 Seawolf is a submarine simulator game designed by John W. Ratcliff and published for MS-DOS systems by Electronic Arts on April 3, 1994. A 3DO Interactive Multiplayer version was planned but never released.

The player takes command of a US  and fights in 33 missions with targets under and above water including Russian attack submarines, destroyers, guided missile cruisers, aircraft carriers and frigates.

The game is a sequel to Electronic Arts' 688 Attack Sub, and has a similar mission structure and variety. Missions might require the player to defend friendly surface ships from attack, or sink those of the enemy. Other missions have their focus entirely underwater, with the player similarly either defending friendly submarines or hunting enemy missile and attack boats. While missions in Seawolf are pre-scripted, there are a number of initial setups which provides some variation in a mission's precise starting conditions.

The game's opponents include the Soviet , and  nuclear-powered attack submarines, which often guard  or  ballistic missile submarines. Some missions may pit the player against the quiet  diesel-electric submarine.

Seawolf models the ocean environment, including thermal layers which can be used to deflect enemy sonar and hide the player's submarine. Sonar plays a central role in the game, and the player has access to the submarine's spectrographic 'waterfall' display which is used to detect and classify contacts. Additionally, the game includes marine life, such as whales and schools of fish, that could generate noise or reflect active sonar and create additional contacts.

Like its predecessor, Seawolf allows two players, on different PCs, to play each other via a modem, or null-modem cable, and adds the option of using an IPX local network which can provide a more reliable connection.

Reception
Computer Gaming World in May 1994 said that "certain hard-core simulation features have been left out to enhance overall playability, but the state-of-the-art graphics, tremendous music by the Fat Man, and mind blowing sound effects all combine to lock this product dead-on-target". In June 1994 it criticized the game's unrealistic weapons load, "deficient" manual, "poor" AI, and lack of game balance, but said that "the game is still a whole heck of a lot of fun. This is definitely a game for someone who wants to enjoy a few hours of blowing up Russian ships, and not for the next Admiral Nimitz". The magazine concluded that "as a simulation, Seawolf is a dud; as a game, it's a solid effort and a worthwhile addition to any naval gamer's shelf".

References

External links
 http://www.ibiblio.org/GameBytes/issue18/greviews/seawolf/seawolf2.html
 
 SSN-21 Seawolf multiplayer manual

1994 video games
Cancelled 3DO Interactive Multiplayer games
DOS games
DOS-only games
Electronic Arts games
Multiplayer and single-player video games
Submarine simulation video games
Video games developed in the United States
Video games scored by George Sanger
Roberto Salmeron. Roberto Aureliano Salmeron (June 16, 1922 – June 17, 2020) was a Brazilian electrical engineer and experimental nuclear physicist and an emeritus Research Director at the French National Centre for Scientific Research (CNRS).

Salmeron was born in São Paulo. He did his undergraduate studies in electrical engineering at the Escola Politécnica da Universidade de São Paulo, in São Paulo, and in physics in the Federal University of Rio de Janeiro (then named Universidade do Brasil), in Rio de Janeiro. From 1947 to 1950, he worked as researcher and physics instructor at the Escola Politécnica and in the Department of Physics of the Faculty of Philosophy, Sciences and Letters of the University of São Paulo, where he studied cosmic radiation under Italian physicists Gleb Wataghin and Giuseppe Occhialini. From 1950 to 1953, Salmeron worked at the recently created Centro Brasileiro de Pesquisas Físicas (Brazilian Center of Physical Research) in Rio. In São Paulo and Rio, Salmeron was contemporary of a brilliant generation of young Brazilian physicists, such as César Lattes, José Leite Lopes, Oscar Sala, Mário Schenberg, Marcelo Damy de Souza Santos and Jayme Tiomno.

From 1953 onwards, Salmeron lived in Europe, first doing his Ph.D. from 1953 to 1955 at the University of Manchester, under Patrick Blackett, Nobel Prize winner of Physics, and then as an associate researcher in the European Organization for Nuclear Research (CERN), in Geneva, Switzerland, from 1955 to 1963.

In 1963, Salmeron returned to Brazil and accepted a post as professor of physics in the newly created Universidade de Brasília. Unfortunately, the military dictatorship repressed strongly the faculty with liberal and leftist ideas and he joined 223 other professors in protest, who resigned from the University in October 1965.

In 1966 Salmeron left definitely Brazil and went to work in Europe at CERN again, where he had an important role in experiments attempting to discover the quark–gluon plasma. Afterwards (1967) he worked at the École Polytechnique in Paris, France, one of the most important schools of engineering in the world.

References

Bibliography 
 R Aldrovandi, A Santoro and J M Gago (eds): Roberto Salmeron Festschrift: a Master and a Friend. AIAFEX, Rio de Janeiro. .
 Conto dos 13 Príncipes, Palaiseau 2002

External links
 Profile: Physics as Amusement. Roberto Salmeron. Ciência Hoje Magazine 31 (185). PDF (In Portuguese)
 

1922 births
20th-century Brazilian engineers
20th-century Brazilian  physicists
21st-century Brazilian engineers
21st-century Brazilian  physicists
Brazilian electrical engineers
Brazilian nuclear physicists
Brazilian people of Spanish descent
Brazilian expatriate academics
2020 deaths
University of São Paulo alumni
Scientists from São Paulo
Federal University of Rio de Janeiro alumni
French National Centre for Scientific Research scientists
People associated with CERN
Brazilian expatriates in the United Kingdom
Brazilian expatriates in Switzerland
Research directors of the French National Centre for Scientific Research
Seam. Seam may refer to:

Science and technology
 Seam (geology), a stratum of coal or mineral that is economically viable; a bed or a distinct layer of vein of rock in other layers of rock
 Seam (metallurgy), a metalworking process the joins the ends of two sheet metal edges
 Seam (sewing), the line where two or more layers of fabric are held together by stitches.
Seam (unit), various obsolete units of measurement
 Can seamer, a machine used to seal a lid to a can body, such as in paint or food cans
 JBoss Seam, a Java application framework by JBoss
 Seam carving, an image resizing algorithm
 Sun Enterprise Authentication Mechanism, or SEAM, an implementation of Kerberos protocol for the Solaris operating system

Sports
 Quarter seam, a thread on the surface of a cricket ball
 Seam bowling, in cricket, refers to bowling with the main seam upright
 Seam route, a passing route in football

Other uses
 Seam (band), an indie rock band from Chicago, Illinois
 SEAM, the ICAO airport code for Chachoan Airport in Ambato, Ecuador
 Seam, a character from the video game Deltarune

See also
 SEAMS
 Seamless (disambiguation)
Seem (disambiguation)
Seim (disambiguation)
Miter joint. A miter joint (mitre in British English) is a joint made by cutting each of two parts to be joined, across the main surface, usually at a 45° angle, to form a corner, usually to form a 90° angle, though it can comprise any angle greater than 0 degrees. It is called beveling when the angled cut is done on the side, although the resulting joint is still a miter joint. 

For woodworking, a disadvantage of a miter joint is its weakness, but it can be strengthened with a spline (a thin wafer of wood inserted into a slot, usually arranged with the long grain of the spline across the short grain of the frame timber). There are two common variations of a splined miter joint, one where the spline is long and runs the length of the mating surfaces and another where the spline is perpendicular to the joined edges.

Common applications include picture frames, pipes, and molding.

Non-perpendicular joints

For miter joints occurring at angles other than 90°, for materials of the same cross-section the proper cut angle must be determined so that the two pieces to be joined meet flush (i.e. one piece's mitered end is not longer than the adjoining piece). To find the cut angle divide the angle at which the two pieces meet by two. Technically, two different cut angles are required; one for each piece, where the second angle is 90° plus the aforementioned cut angle, but due to angular limitations in common cutting implements (hand circular saws, table saws) a single angle is required and is used to cut the first piece in one direction and the second piece in the opposite direction.

See also
 Mason's miter
 Miter box
 Miter clamp
 Miter saw
Miter square
 Pipe notching

References

Further reading
 Adamson, John, "The making of the mitre plane", Furniture & Cabinetmaking, issue 270, May 2018, pp. 44–9

External links

 Miter Saw Calculator
 Verhoeff, Tom and Koos Verhoeff, PDF "The Mathematics of Mitering and Its Artful Application", Bridges Leeuwarden: Mathematical Connections in Art, Music, and Science, Proceedings of the Eleventh Annual Bridges Conference, in The Netherlands, pp. 225–234, July 2008.

Joinery
Woodworking
Metalworking
X-41 Common Aero Vehicle. 

X-41 is the designation, initiated in 2003, for a still-classified United States military spaceplane. The X-41 is now part of the FALCON (Force Application and Launch from Continental United States) program sponsored by DARPA and NASA.

Description
Specifications or photos of the X-41 program have not been released to the public; thus little is known about its goals. It has been described as an experimental maneuvering reentry vehicle capable of transporting a 1,000-pound payload on a sub-orbital trajectory at hypersonic speeds and releasing that payload into the atmosphere. The word "Aero" in "Common Aero Vehicle" stood for "aeroshell", not "aerospace", because the CAV was a common aerothermodynamic shell for varying and multiple payloads. The technology necessary for the X-41 is not known and reportedly has yet to be developed. However, it is believed to be a new form of hypersonic propulsion capable of exceeding Mach 7, perhaps reaching .

See also
Hypersonic Technology Vehicle 2
Prompt Global Strike

References

External links
GlobalSecurity.org: X-41 
Spacedaily.com: CAV
Pentagon Has Far-Reaching Defense Spacecraft in Works, Washington Post, March 16, 2005

Spaceplanes
2000s United States experimental aircraft
DARPA
Space launch vehicles of the United States
Forward Gas Engine Company. Forward Gas Engine Company was an engineering company making stationary internal combustion gas engines in Nechells, Birmingham, England.

The most famous engineer to work at the plant was Frederick William Lanchester around 1895, who made various improvements to their engines, including a self-starting device, whilst designing the first British petrol motor car, leading to the Lanchester Motor Company.

Defunct companies based in Birmingham, West Midlands
Manufacturing companies based in Birmingham, West Midlands
Hiller X-18. The Hiller X-18 was an experimental cargo transport aircraft designed to be the first testbed for tiltwing and V/STOL (vertical/short takeoff and landing) technology.

Development

Design work started in 1955 by Stanley Hiller Jr and Hiller Aircraft Corporation received a manufacturing contract and funding from the United States Air Force to build the only X-18 built, serialized 57-3078.

To speed up construction and conserve money, the plane was constructed from scavenged parts including a Chase YC-122C Avitruc fuselage, 49-2883, and turboprops from the Lockheed XFV-1 and Convair XFY-1 Pogo experimental fighter programs. The tri-bladed contra-rotating propellers were a giant 16 ft (4.8 m) across. The Westinghouse turbojet engine had its exhaust diverted upwards and downwards at the tail to give the plane pitch control at low speeds. Hiller nicknamed their X-18 the Propelloplane for public relations purposes.

Service history

Preliminary testing occurred at Moffett Field Naval Air Station, CA. The first flight (hop) was on 11/20/1959 followed by the first real flight on 11/24/1959 with Hiller test pilots George Bright and Bruce Jones.  Further test flights were held at Edwards AFB, ultimately recording 20 flights. A number of problems plagued the X-18 including being susceptible to wind gusts when the wing rotated, acting like a sail. In addition the turboprop engines were not cross-linked, so the failure of one engine meant the airplane would crash. Thrust control was through throttle changes, which were too slow for acceptable height and roll control.

On the 20th and final flight in July 1961, the X-18 had a propeller pitch control problem when attempting to convert to a hover at  and went into a spin. The crew regained control and landed, but the X-18 never flew again. However ground testing of the tiltwing concepts continued. Eventually a VTOL Test Stand was built on which the X-18's vertical takeoff and landing and hover control was to be tested. One engine run was successfully conducted to the full  wheel height on the VTOL Test Stand. The program was canceled on January 18, 1964, before further VTOL Test Stand testing could be conducted, and the X-18 was cut up for scrap.

The program proved several things that contributed to further tilt-wing VSTOL technology programs:
cross-shafting between the engines was necessary in order to avoid loss of control in the event of an engine failure.
direct propeller pitch control was necessary for precise height and lateral control during VTOL and hover.

This knowledge was employed in the successful development and flight tests of the Tri-Service XC-142A tilt-wing VSTOL transport.

Specifications (X-18)

See also

References

External links

 Hiller X-18
 X-18 Images
 X-18 Images and History

Edwards Air Force Base
X-18, Hiller
Tiltwing aircraft
Aircraft with contra-rotating propellers
X-18
Aircraft first flown in 1959
Twin-engined four-prop tractor aircraft
SIU. SIU may 
 Seafarers International Union of North America, an organization of labor unions
 Segment of Independent Utility, a highway engineering term for divisions of large-scale construction projects; see 
 Shinawatra University, in Bangkok, Thailand
 S.I.U. (film), a 2011 South Korean action film
 SIU, a 2019 Vocaloid album
 Siuna Airport in Nicaragua (IATA Code) 
 Slave In Utero, the pen name of Lee Jong-hui, author of the South Korean webcomic Tower of God
 Southern Illinois University, a university system in the United States
 Southern Illinois University Carbondale, the system's flagship university
 Special Investigations Unit (Ontario), a police oversight agency in Ontario, Canada
 Special Investigating Unit, South African law enforcement agency
 Symbiosis International University, a private university in India

Siu may refer to:

 Shao, a Chinese surname, sometimes transliterated as Siu
 Siu, a god-hero of Torres Strait Islander people
 Xiao (surname), a Chinese surname, sometimes transliterated as Siu

Siu (celebration) a celebration which has become increasingly popular and was made by Cristiano Ronaldo

See also
 Special Investigations Unit (disambiguation)
Elinvar. Elinvar is a nickel–iron–chromium alloy notable for having a modulus of elasticity which does not change much with temperature changes.

Metal
The name is a contraction of the French  ('invariable elasticity'). It was invented by Charles Édouard Guillaume, a Swiss physicist who also invented Invar, another alloy of nickel and iron with very low thermal expansion. Guillaume won the 1920 Nobel Prize in Physics for these discoveries, which shows how important these alloys were for scientific instruments.

Elinvar originally consisted of 52% iron, 36% nickel, and 12% chromium. It is almost non-magnetic, and corrosion resistant.

Other variations of the Elinvar alloy are 
 Iron- and cobalt-based ferromagnetic Elinvar alloy
 Manganese- and chromium-based antiferromagnetic Elinvar alloy
 Palladium-based non-magnetic Elinvar alloy

The largest use of Elinvar was in balance springs for mechanical watches and chronometers.  A major cause of inaccuracy in watches and clocks was that ordinary steels used in springs lost elasticity slightly as the temperature increased, so the balance wheel would oscillate more slowly back and forth, and the clock would lose time.  Chronometers and precision watches required complex temperature-compensated balance wheels for accurate timekeeping.  Springs made of Elinvar, and other low temperature coefficient alloys such as Nivarox that followed, were minimally affected by temperature, so they made the temperature-compensated balance wheel obsolete.

References

Ferrous alloys
Nickel alloys
Horology

External links

 . Explanation of Elinvar use in pocket watch balance wheel hair springs.
Shot welding. Shot welding is a type of electric resistance welding which, like spot welding, is used to join two pieces of metal together. The distinguishing feature is that in shot welding, strips and sheets of metal (usually stainless steel) are "sewed" together with rows of uniform spot welds. The weld is achieved by clamping the two pieces together then passing a large electric current through them for a short period of time.  Shot welding was patented by Earl J. Ragsdale, a mechanical engineer at the Edward G. Budd Manufacturing Company in 1932 to weld stainless steel. This welding method was used to construct the first stainless steel train,  Pioneer Zephyr, in 1934, and became the standard construction technology for railroad passenger cars thereafter.

Method
In the early 20th century, the Edward G. Budd Manufacturing Company had been innovative in the field of sheet metal fabrication, and had revolutionized the construction of automotive bodies in steel during the 1920s. Edward Budd and his employees, notably Earl Ragsdale, recognized the important metallurgical characteristics of 18/8 stainless steel (known today as SAE 304 austenitic stainless steel) and further developed a spot welding process to take advantage of the oxidized layer on the surface of stainless steel. Heat treating the 18-8 stainless steel leaves the metal with non-magnetic and ductile properties. Repeatedly reheating the metal to 1000–1100°C impairs the mechanical and chemical properties of the metal. The metal becomes susceptible to corrosion due to carbide precipitation, and loses fatigue resistance.  The important factor in controlling the metal's properties is the dwell time at those temperatures. Using a controlled time element and recorder, a power supply with smooth current, and very brief high currents, a satisfactory spot weld may be produced.

The corona of the shot weld should not exist on the metal, and the equipment used produces satisfactory welds with a smaller than normal diameter. Sufficient electrode force is applied to hold the two sheets of metal together and the peak current rapidly creates a forge weld at the interface between the two sheets, producing a small nugget of weld metal, which when cooled results in a shear-resistant metal interface. Good shotwelds have twice the shear strength of a rivet of similar diameter and can be placed 50% closer together. When done properly, distortion, which is a problem in fusion welding processes, is eliminated.

References

Welding
Budd Company