omniomni/omni-engineering huggingface dataset:
9,10-Diphenylanthracene. 9,10-Diphenylanthracene is a polycyclic aromatic hydrocarbon. It has the appearance of a slightly yellow powder. 9,10-Diphenylanthracene is used as a sensitiser in chemiluminescence. In lightsticks it is used to produce blue light.  It is a molecular organic semiconductor, used in blue OLEDs and OLED-based displays.

See also
 2-Chloro-9,10-diphenylanthracene, a chlorinated derivative

References

External links
 Polycyclic aromatic hydrocarbons, Australian National Pollutant Inventory

Organic semiconductors
Anthracenes
Rubble. Rubble is broken stone, of irregular size, shape and texture; undressed especially as a filling-in. Rubble naturally found in the soil is known also as 'brash' (compare cornbrash). Where present, it becomes more noticeable when the land is ploughed or worked.

Building

"Rubble-work" is a name applied to several types of masonry. One kind, where the stones are loosely thrown together in a wall between boards and grouted with mortar almost like concrete, is called in Italian "muraglia di getto" and in French "bocage". In Pakistan, walls made of rubble and concrete, cast in a formwork, are called 'situ', which probably derives from Sanskrit (similar to the Latin 'in situ' meaning 'made on the spot').

Work executed with more or less large stones put together without any attempt at courses is called rubble walling. Where similar work is laid in courses, it is known as coursed rubble. Dry-stone walling is somewhat similar work done without the use of mortar. It is bound together by the fit of the stones and the regular placement of stones which extend through the thickness of the wall. A rubble wall built with mortar will be stronger if assembled in this way.

Rubble walls in Malta 

Rubble walls () are found all over the island of Malta. Similar walls are also frequently found in Sicily and the Arab countries. The various shapes and sizes of the stones used to build these walls look like stones that were found in the area lying on the ground or in the soil.  It is most probable that the practice of building these walls around the field was inspired by the Arabs during their rule in Malta, as in Sicily who were also ruled by the Arabs around the same period. The Maltese farmer found that the technique of these walls was very useful especially during an era where resources were limited. Rubble walls are used to serve as borders between the property of one farm from the other. A great advantage that  rubble walls offered is that when heavy rain falls, their structure would allow excessive water to pass through and therefore, excess water will not ruin the products. Soil erosion is minimised as the wall structure allows the water to pass through but it traps the soil and prevents it from being carried away from the field. One can see many rubble walls on the side of the hills and in valleys where the land slopes down and consequently the soil is in greater danger of being carried away.

Rubble in Britain 
In the British Islands, many mediaeval and post-mediaeval buildings are built of small natural stones, called rubble.
As examples see the descriptions in two official list entries, provided by Historic England:
No. 1191625 – Parish Church of the Holy Trinity, Chuckfield
No. 1139238 – Church of St Mary, Longnewton, 1856/57

See also
Core-and-veneer
Ruin
Rubble trench foundation

References

External links

 Example of a coursed rubble wall in Malta

Building materials
Building stone
Natural materials
Building engineering
Stone (material)
Tetracene. Tetracene, also called naphthacene, is a polycyclic aromatic hydrocarbon. It has the appearance of a pale orange powder. Tetracene is the four-ringed member of the series of acenes.

Tetracene is a molecular organic semiconductor, used in organic field-effect transistors (OFETs) and organic light-emitting diodes (OLEDs). Tetracene can be used as a gain medium in dye lasers as a sensitiser in chemoluminescence. Napthacene is the main component of the tetracycline class of antibiotics.

History and Synthesis 
In 1884, W. Roser attempted to synthesize a compound called "Aethindiphtalyls" (literally "ethyne diphthalyl") by heating 3 parts of phthalic anhydride, 3 parts of succinic acid and one part of sodium acetate according to Siegmund Gabriel's procedure. And then he found that there was a brick-red byproduct was produced in a large amount in the reaction, which was called "Isoäthindiphtalid" (literally "Isoethyne diphthalide") and founded to be an isomer of "Aethindiphtalyls". In 1898, Gabriel and Ernst Leupold did a study on the byproduct and confirmed it was a new class of compound containing 4 rings.

In the same document, Gabriel and Leupold reported their synthesis of tetracene by condensating two moles of phthalic anhydride with a mole of succinic acid into a quinone then reduced with zinc dust.  They named in naphthacene, likely as portmanteau of naphthalene and anthracene. Modern nomenclature for polyacenes, including tetracene, was introduced by Erich Clar in 1939. Clar also developed a new route to synthesize tetracene from the Friedel-Crafts acrylation between phthalic anhydride and tetralin catalyzed by AlCl3, ZnCl2 and NaCl involving Clemmensen reduction, forming 5,12-dihydrotetracene then dehydrogenated by chloranil to form tetracene.

German physicist Jan Hendrik Schön claimed to have developed an electrically pumped laser based on tetracene during his time at Bell Labs (1997–2002). However, his results could not be reproduced, and this is considered to be a scientific fraud.

In May 2007, Japanese researchers from Tohoku University and Osaka University reported an ambipolar light-emitting transistor made of a single tetracene crystal.  Ambipolar means that the electric charge is transported by both positively charged holes and negatively charged electrons.  

In 2024, it was used to produce lower-energy excitations in solar cells in a process known as singlet fission. An interface layer between tetracene and silicon transfers them into the silicon layer, where most of their energy can be converted into electricity.

See also 
 Tetraphene, also known as benz[a]anthracene
 Doxycycline

Notes 
Daniel Oberhaus, New Designs Could Boost Solar Cells Beyond Their Limits, Wired, July 11th 2019

References

Polycyclic aromatic hydrocarbons
Organic semiconductors
Laser gain media
Tetracyclic compounds
Acenes
Spaceway-2. Spaceway-2  is part of DirecTV's constellation of direct broadcast satellites. The satellite was launched via an Arianespace Ariane 5 ECA rocket from Kourou, French Guiana on 16 November 2005. Its operational position is in geosynchronous orbit  above the equator at 99.2° West longitude. Spaceway-2 is a Boeing 702-model satellite with a 12-year life expectancy. It is expected to support high-definition television to DirecTV customers with its Ka-band communications payload. Although Spaceway-2 was originally built by Boeing to be used for broadband Internet access via Hughes Network Systems, it has been retrofitted to deliver HD local channels (NBC, ABC, CBS, and Fox) to numerous markets nationwide.

On 19 April 2006, the satellite was delivered to DirecTV's control after successful on-orbit testing. Spaceway-2 immediately started broadcasting HD locals to DirecTV customers in eight more markets:  Minneapolis, Minnesota; Sacramento and San Diego, California; Pittsburgh, Pennsylvania; Nashville, Tennessee; Kansas City, Missouri; Columbus, Ohio; and Birmingham, Alabama. Satellites named T10 (launched in 2007) and T11 (launched in 2008), constructed by Boeing, also for use in high-definition television, are bent-pipe Ka-band satellites instead of regenerative satellites, and are being used to continue the expansion of DirecTV's HD services.

Spaceway-2 was originally envisioned as a global Ka-band communications system.

Boeing retrofitted the Spaceway-2 satellite for bent-pipe Ka-band communications for use in high-definition television and disabled the regenerative on-board processing of the original system that was to be used for the Spaceway broadband satellite communications.

T11 is co-located with Spaceway-2 satellites in order to use the 500 MHz of unused spectrum for HDTV broadcasting. This spectrum was originally intended for the broadband internet capabilities of the two Spaceway satellites which were disabled by Hughes Network Systems at the request of DirecTV.

See also 

 Spaceway

References

External links 
 Arianespace Spaceway 2 Launch Info
 Spaceway 2 Launch Press Release

Satellites using the BSS-702 bus
Communications satellites in geostationary orbit
DirecTV
Spaceway. The Spaceway system was originally envisioned as a global Ka-band communications system by Hughes Electronics. When the project to build the system was taken over by Hughes Network Systems, a subsidiary of Hughes Electronics, it was transformed into a phased deployment initially only launching a North American satellite system. This is in comparison to other more ambitious systems such as Teledesic and Astrolink which retained their full global nature and which subsequently failed to complete their systems. Hughes Network Systems working with Hughes Electronics subsidiary Hughes Space and Communications (and subsequently sold to Boeing and called Boeing Satellite Systems and later the Boeing Satellite Development Center) completed and built the North American Spaceway system meant to provide broadband capabilities of up to 512 kbit/s, 2 Mbit/s, and 16 Mbit/s uplink data communication rates with fixed Ka-band satellite terminal antennas sized as small as . The broadband Spaceway system was standardized by Telecommunications Industry Association and European Telecommunications Standards Institute (ETSI) as the Regenerative Satellite Mesh - A Air Interface.

After News Corp purchased a controlling interest in Hughes Electronics, the company sold off its controlling interest in Hughes Network Systems but retained Spaceway-1 and Spaceway-2 for use in the DirecTV satellite television subsidiary of Hughes Electronics. Boeing retrofitted the first two satellites for bent pipe Ka-band communications for use in high-definition television and disabled the regenerative on-board processing of the original system that was to be used for broadband satellite communications.

Despite statements to the contrary in the system's initial filings with the Federal Communications Commission, none of the three satellites have inter-satellite links connecting the satellites directly with each other in space.

Spaceway-1, Spaceway-2 and Spaceway-3 have been launched and Hughes Network Systems had an option to purchase and have Boeing build Spaceway-4.

Spaceway-1 was decommissioned in February 2020 after suffering extensive thermal damage to its batteries in December 2019, forcing the satellite to be moved to a graveyard orbit to prevent the risk of it exploding.

Notes

References

External links 
 Spaceway 3
 Boeing's Original Spaceway Specification and Picture

Communications satellites
Mike Shipley. Michael Shipley (7 October 1956 – 25 July 2013) was an Australian mixing engineer, audio engineer, and record producer. Shipley's music career spanned more than 30 years – mostly working in Los Angeles. At the Grammy Awards of 2012 he won the Best Engineered Album, Non-Classical category for his joint work on  Paper Airplane (April 2011), by Alison Krauss and Union Station. Shipley died in July 2013, aged 56, of an apparent suicide.

Life and career 

Michael Shipley was born on 7 October 1956, in Sydney, Australia; as a teenager he moved with his family to London. He became interested in a recording career while at school in the United Kingdom in the early 1970s. He later recalled, "One of my teachers at grammar school there was a musician who asked me to come down and sing on a record he was making. I walked into this thing called the recording studio, and it just blew my mind. It was, 'This is home,' and I knew instantly and from that point on that all I wanted to do was to work there." Shipley returned to Australia and completed secondary education at Camberwell Grammar School (class of '74) in Melbourne. He then returned to London, where he started as an assistant at Wessex Sound Studios and worked with Sex Pistols and Queen.

His first engineering sessions were during the punk rock explosion of the late 1970s and early 1980s and included recordings with the Damned. He worked alongside Robert John "Mutt" Lange for decades. His contemporaries at Wessex include producers Roy Thomas Baker and Chris Thomas, and engineers Tim Friese-Greene and Bill Price. Shipley also worked with Def Leppard on their albums, High 'n' Dry (July 1981), Pyromania (January 1983), Hysteria (August 1987) and Adrenalize (March 1992).

Asked to work with the Cars, Shipley relocated to Los Angeles in 1984. Shipley later relocated to Hawaii for a sabbatical, but returned to Los Angeles to work for Def Leppard, Shania Twain, The Corrs, Anberlin, Aerosmith, Maroon 5, Faith Hill, India.Arie, Kelly Clarkson, Green Day, Nickelback and Alison Krauss.

Death

Shipley died on 25 July 2013. Cause of death, as stated on 9 August 2013 at the memorial service, was an apparent suicide.

Discography 
Recorded work credited to Shipley:

1970s

1980s

1990s

2000s

2010s

References

External links

 
 
 
 An Evening with Mike Shipley
 LA Grapevine November 2006

1956 births
2013 deaths
Australian record producers
Australian audio engineers
Musicians from Sydney
Grammy Award winners
Suicides in California
21st-century Australian guitarists
2013 suicides
ATA Spec 100/iSpec 2200. ATA Spec 100''' and iSpec 2200''' are information standards for aviation maintenance and flight operations published by Airlines for America (formerly Air Transport Association).

These standards provide recommended specifications for the content, structure and deliverables to meet communication requirements [physical, electronic and future technology] of aircraft product technical information.

Current iSpec 2200 comprises a suite of data specifications and data modules for the digital representation and exchange of technical data.

Objective is to:
 Minimize cost and effort expended by operators and OEMs
 Improve information quality and timeliness
 Ensure that manufacturers provide data that meets airline operational needs

History
ATA Spec 100 was originally published in 1956. It established an industry-wide numbering scheme to organize aviation technical documentation as well as content and formatting guidelines for its conventional printed distribution.

ATA Spec 2100 focused on electronic data exchange implemented in SGML.

iSpec 2200 was first published in 2000. It incorporates the previous 100 and 2100 specs which won't be maintained beyond their final 1999 revisions.

References

Aircraft maintenance
Bell P-76. The Bell P-76 was the proposed designation for a production model derivative of the XP-39E, a single-engine American fighter aircraft prototype of World War II.

Design and development
On 26 February 1941 the United States Army Air Corps (USAAC) placed a contract with Bell allowing for the purchase of two XP-39Es (41-19501 and 41-19502) which were envisaged to be a major improvement on the P-39D series. Because of the number of changes proposed the production model was to be called the Bell P-76.

The Bell P-76 was proposed to address the poor high-altitude performance of the P-39 Airacobra by incorporating a new and thicker wing with a symmetrical airfoil; the section chosen was NACA 0018 at the wing-root tapering to an NACA 23009 at the tip. Although the new wing has often been referred to as a laminar flow type, this was not the case. The wing span was increased to 35 ft 10 in (10.9 m) and the area to 236 ft2 (21.9 m2), the thicker wing allowing an increase in the fuel capacity to 150 US gallons (568 L).

Design of a new Allison V-1710-E9 was also underway. This version, which had the military designation of V-1710-47, used a two-stage mechanical supercharger to increase the engine power at altitude. However, this engine went through so many design changes that it ended up being almost identical to the later V-1710-93 which was fitted in the XP-63A.

Another change was the engine bay was modified to accept a more powerful engine in lieu of the V-1710. Its origins lie in the 1941 project to equip three P-39D (41-19501, 41-19502 and 42-7164) with the Continental V-1430-1 liquid-cooled supercharged engine. The resultant XP-39E had a symmetrical airfoil wing with square wingtips, an elongated fuselage to accommodate the larger engine, and revised air intakes and radiators. The three prototypes each had a different tailfin. Since the Continental engine was not available at rollout, the prototypes flew with Allison V-1710-47 engines. In 1942, the XP-39E was redesignated P-76. Although 4,000 aircraft were initially ordered, the order was cancelled to permit the Bell factory to manufacture B-29 Superfortress bomber aircraft under license from Boeing. Many of the lessons learned in the P-76 were implemented in the subsequent P-63 Kingcobra.

Specifications (P-76)

See also

References

Citations

Bibliography

 Bowers, Peter M. "Airborne Cobra Pt.II". Airpower magazine, Vol.9, No.1, January 1979.

Bell XP-46
P-076
Mid-engined aircraft
Single-engined tractor aircraft
Low-wing aircraft
1940s United States fighter aircraft
Aircraft with retractable tricycle landing gear
Curtiss XP-71. The Curtiss XP-71 was a 1941 American proposal for an exceptionally large heavy fighter design. It was intended to serve as an extreme-range interceptor and escort fighter. While significant progress was made in the design phase, no prototypes were ever built, and the design was abandoned in 1943.

Design and development
The proposed aircraft was to have a pressurized cockpit. Power would be provided by two Pratt & Whitney R-4360 Wasp Major radial engines each driving a set of pusher contra-rotating propellers.

Based on studies of heavy, long-range fighters that had been undertaken prior to the American involvement in World War II, the United States Army Air Forces initially ordered two prototypes in November 1941. The major role for the proposed aircraft was to act as an "escort" fighter to protect heavy bombers that would have to operate over occupied Europe even if Britain was conquered.

Developed around two turbocharged  R-4360s driving pusher propellers, the XP-71 would have been the largest fighter aircraft built in the war.

The final XP-71 design would have been larger than the contemporary B-25 and was considered a complex industrial project that would have taxed the resources of the Curtiss company as it was evident that development time would stretch out well beyond the projected need for the type. 

At the time, Curtiss facilities were completely committed to producing existing aircraft; due to the need to keep their production lines open for the current types on order and with shifting combat requirements, the USAAF reconsidered the need for the project before prototype construction had begun. As conditions changed and it was clear that Britain would continue to be available for forward bases, the requirement for the advanced fighter project led to the cancellation of the XP-71 in early 1942.

Specifications (XP-71, as designed)

See also

References

Notes

Bibliography

 Dorr, Robert F. and Donald, David. Fighters of the United States Air Force. London: Temple, 1990. .
 Jones, Lloyd S. U.S. Fighters: Army-Air Force 1925 to 1980s. Fallbrook, California: Aero Publishers, Inc., 1975. .

External links

P-71
Twin piston-engined pusher aircraft
High-wing aircraft
Cancelled military aircraft projects of the United States
Aircraft with contra-rotating propellers
Aircraft with retractable tricycle landing gear
Vultee XP-68 Tornado. The Vultee XP-68 Tornado was a proposed American World War II-era high-altitude interceptor aircraft. It was based on the experimental XP-54 Swoose Goose and powered by the Wright R-2160 Tornado 42-cylinder radial engine driving a set of contra-rotating propellers in a twin-boom pusher configuration. When the engine was cancelled on 22 November 1941, the XP-68 was also cancelled.

Specifications

See also

References

Citations

Bibliography
 Andrade, John M. U.S. Military Aircraft Designations and Serials since 1909. Earl Shilton, Leicester, UK: Midland Counties Publications, 1979.  (Hardcover),  (Softcover).
 Angelucci, Enzo and Peter Bowers. The American Fighter, The Definite Guide to American Fighter Aircraft from 1917 to the Present. New York: Orion Books, 1987. .
 
 Thompson, Jonathan. Vultee Aircraft 1932–1947. Santa Ana, CA; Narkiewicz/Thompson, 1992. .
 Wagner, Ray. American Combat Planes of the 20th Century: A Comprehensive Reference. Reno, Nevada: Jack Bacon & Co, 2004. .

External links

 Vultee XP-68 Fact Sheet at the National Museum of the USAF
 Vultee XP-68

XP-68
Cancelled military aircraft projects of the United States
Single-engined pusher aircraft
Twin-boom aircraft
Aircraft with contra-rotating propellers
SGI Prism. The Silicon Graphics Prism is a series of visualization computer systems developed and manufactured by Silicon Graphics (SGI). Released in April 2005, the Prism's basic system architecture is based on the Altix 3000 servers, but with graphics hardware.
The Prism uses the Linux operating system and the OpenGL software library.

Three models of the SGI Prism are Power, Team and Extreme levels.
 The Power level supports two to eight Itanium 2 processors, up to 96 GB of memory and two to four graphics pipelines.
 The Team level supports 8 to 16 Itanium 2 processors, up to 192 GB of memory and four to eight graphics pipelines.
 The Extreme level supports 16 to 256 Itanium 2 processors, up to 3 TB of memory and 4 to 16 graphics pipelines.

The graphics pipelines for the Prism are ATI FireGL cards based on either the R350 or R420 GPUs.

References

Prism
Prism
Very long instruction word computing
64-bit computers
Honda P50. The Honda P50 (known as the P25 in some markets) was introduced in June 1966. It was the last motor-wheel moped design by Honda (and probably by any other large manufacturer).

The P50 features a step-through frame made from steel pressings, leading-link front suspension, plastic fenders and chainguard. The fuel tank is located above the rear fender, and the key distinguishing feature of the design is the  engine being located at the extreme lower left rear of the frame, with all of the driveline components housed within the large hub of the rear wheel.

The engine is also 4-stroke — unusual when almost all pedal-equipped mopeds used simpler 2-strokes. Soichiro Honda disliked the sharp noise of 2-strokes, and the 4-stroke does not require oil to be mixed with the gasoline at every fill-up.

References

 Infobox specifications from these pages on 2008-02-23: 
http://www.honda.co.jp/sou50/Hworld/Hall/2r/67.html
http://www.honda.co.jp/pressroom/library/motor/scooter/pal/t_index.html

External links
Little Honda P25  brochure at Product Design Data Base 

P50
Motorcycles introduced in 1966