omniomni/omni-engineering huggingface dataset:
Crevasse splay. A crevasse splay is a sedimentary fluvial deposit which forms when a stream breaks its natural or artificial levees and deposits sediment on a floodplain. A breach that forms a crevasse splay deposits sediments in similar pattern to an alluvial fan deposit. Once the levee has been breached the water flows out of its channel. As the water spreads onto the flood plain sediments will start to fall out of suspension as the water loses energy. The resulting deposition can create graded deposits similar to those found in Bouma sequences. In some cases crevasse splays can cause a river to abandon its old river channel, a process known as avulsion. Breaches that form a crevasse splay deposits occur most commonly on the outside banks of meanders where the water has the highest energy. Crevasse splay deposits can range in size. Larger deposits can be  thick at the levee and spread  wide, while smaller deposits may only be  thick.

See also

References

External links
A crevasse splay along the Columbia River

Rivers
Fluvial landforms
Leg extension. The leg extension is a resistance weight training exercise that targets the quadriceps muscle (m. quadriceps femoris) in the legs. The exercise is done using a machine called the Leg Extension Machine. There are various manufacturers of these machines and each one is slightly different. The leg extension is an isolated exercise targeting one specific muscle group, the quadriceps. 



History 
The leg extension machine was created by American fitness guru Jack LaLanne in the 1950s. The first prototype is recognized to have been made under Gustav Zander, but labeled the machine as a form of “mechanotherapy” along with other machines that extended the knee and ankle. The machine was made to target the quadriceps. The exact method of inventing the leg extension machine is not consistently recorded, but in most cases, it is attributed to LaLanne.

References 

Weight training exercises
Ultra-short baseline acoustic positioning system. USBL (ultra-short baseline, also known as SSBL for super short base line) is a method of underwater acoustic positioning. A USBL system consists of a transceiver, which is mounted on a pole under a ship, and a transponder or responder on the seafloor, on a towfish, or on an ROV. A computer, or "topside unit", is used to calculate a position from the ranges and bearings measured by the transceiver.

Mechanism 
An acoustic pulse is transmitted by the transceiver and detected by the subsea transponder, which replies with its own acoustic pulse. This return pulse is detected by the shipboard transceiver. The time from the transmission of the initial acoustic pulse until the reply is detected is measured by the USBL system and is converted into a range.

To calculate a subsea position, the USBL calculates both a range and an angle from the transceiver to the subsea beacon. Angles are measured by the transceiver, which contains an array of transducers. The transceiver head normally contains three or more transducers separated by a baseline of 10 cm or less, hence the "short baseline" name. A method called “phase-differencing” within this transducer array is used to calculate the direction to the subsea transponder.

The presence of environmental noise reduces USBL positioning accuracy. Combining Kalman filtering with an element array has been used to filter the signals and improve accuracy, using the minimum mean-square error rule.

Applications 
USBLs are used in "inverted" (iUSBL) configurations, with the transceiver mounted on an autonomous underwater vehicle, and the transponder on the ship/shore that launches it. In this case, the "topside" processing happens inside the vehicle to allow it to locate the transponder for applications such as automatic docking, target tracking, and the exchange of text messages.

References

External links 
 
 
 

Navigation
Surveying
Getrag F25 transmission. The Getrag F25 manual transmission was fitted to many vehicles in the European Opel production line-up including the Opel Calibra. It is a five-speed transmission with the following configuration:
 Front-wheel drive
 Transverse-mounted
 Clutch diameter 
 Dry weight ; wet

Gear ratio

 Differential ratio 3.82:1 or 4.05:1

Designation
There have been many references to the numbering designation that Opel elected to utilise for gearboxes; one of the more common arguments is that it refers to the ft·lbf torque capacity of the gearbox, in this case being a  torque limit. Other arguments include that it is simply related to the engine size (the F25 gearbox was often fitted to 2.5-litre engine vehicles).

This argument, that engine size is the justification for the numbering, could be disputed as the Opel Vectra B with the 2.6-litre V6 engine was fitted with an F23 transmission.

As an example, the F25 transmission was fitted to the Opel Calibra 2.5-litre models (C25XE and X25XE engine models).

The numerical designations usually indicate the maximum torque rating of the gearbox in newton metres. For example, the F40 gearbox is rated at 400 Nm or 295 ft-lbs torque; the M32 gearbox is rated at 320 Nm; the F17 gearbox is rated at 170 Nm, and so on.

External links
 opel-infos.de 

General Motors transmissions
Getrag transmissions
Edison Welding Institute. EWI, previously known as Edison Welding Institute, is a nonprofit engineering and technology organization dedicated to developing, testing, and implementing advanced manufacturing technologies for industry. Headquartered in Columbus, Ohio, USA, EWI offers applied research, manufacturing support, and strategic services to leading manufacturers in the aerospace, automotive, defense, energy, government, heavy manufacturing, medical and electronics sectors. Approximately 150 employees staff the institute. EWI holds numerous patents for various materials joining and manufacturing technologies.

The organization was founded in 1984 in a research park adjacent to Ohio State University, when then Ohio Governor Richard Celeste established the Thomas Edison Program, an initiative to establish the Edison Technology Excellence Centers within the state, including a center for welding research and development. Today EWI operates independently and is considered one of the leading engineering and technology innovator for advanced manufacturing  in North America.

EWI has offices and laboratories in Columbus, Ohio and Buffalo, New York.

References

External links
Official Website
Wire Cold Welder

Welding organizations
Non-profit organizations based in Ohio
Colleges, schools, and departments of Ohio State University
Organizations established in 1984
Urban wild. An urban wild is a remnant of a natural ecosystem found in the midst of an otherwise highly developed urban area.

One of the most expansive efforts to protect and foster urban wilds is the aptly titled "Urban Wilds program" conducted in Boston, which had its start in 1977 off the back of a 1976 report by the Boston Planning & Development Agency (BPDA), formerly the Boston Redevelopment Authority (BRA).

Utility

Urban wilds, particularly those of several acres or more, are often intact ecological systems that can provide essential ecosystem functions such as the filtering of urban run-off, the storing and slowing the flow of stormwater, amelioration of the warming effect of urban development, and generally benefiting local air quality.

Typically, urban wilds are home to native vegetation and animal life as well as some introduced species. Urban wilds are vital to species of migratory birds that have nested in a given area since prior to its urbanization.

Preservation
Without formal protection, urban wilds are vulnerable to development.  However, achieving formal protection of a large urban wild can be difficult. Land tenure of a single ecological area can be complex, with multiple public and private entities owning adjacent properties.

Key strategies used in the preservation of urban wilds have included conservation restrictions that keep complex land tenure systems in place while protecting the entire landscape. Public/private partnerships have also been successful in protecting urban wilds.

The urban wilds prioritized by municipalities tend to be partial wetlands that perform a range of ecological services while contributing to the biological diversity of the region.

Passive parks

There is some discussion about whether natural areas that are not at an appropriate scale to perform significant ecosystem services should instead be categorized as passive parks as opposed to urban wilds.  Smaller urban wilds are used for passive recreation and have less value to the city in terms of enhancing ecosystem function.

Notes

References 

 
 
 
 
 

Urban planning
Parks
Ecology
Ralph Holley Keefler. Major General Ralph Holley Keefler,  (September 12, 1902 – September 17, 1983) was a Canadian soldier and businessman. He was commander of the 3rd Canadian Infantry Division during the final stages of World War II and was chairman and president of Northern Electric (now Nortel Networks).

Born in Weston, Ontario, the son of Joseph Keefler and Margaret Isabel Holley, he received a B.A.Sc. in Mechanical Engineering from the University of Toronto in 1924 and later joined the Bell Telephone Company. During World War II, he was the Major-General in command of the 3rd Canadian Infantry Division.

After the war, he became chairman and president of Northern Electric. In 1965 he was president of the Canadian Chamber of Commerce.

See also
 John Roth

External links
 
Generals of World War II

References

|-

1902 births
1983 deaths
Businesspeople from Toronto
Canadian Companions of the Distinguished Service Order
Canadian Commanders of the Order of the British Empire
People from Weston, Toronto
Military personnel from Toronto
Canadian generals
University of Toronto alumni
Nortel employees
Directors of Nortel
Canadian Army generals of World War II
Frederick Mills. Frederick Mills may refer to:

Sir Frederick Mills, 1st Baronet (1865–1953), English iron and steel manufacturer and politician
Frederick Mills (engineer) (1898–1949), Chief Mechanical Engineer of the Western Australian Government Railways
Frederick Mills (cricketer) (1898–1929), English cricketer
Frederick Mills (rugby union) (1849–1904), English rugby union player
Frederick C. Mills (1892–1964), American economist
Fred Mills (footballer) (1910–1944), English footballer
Freddie Mills (1919–1965), English boxer
Fred Mills (musician) (1935–2009), Canadian trumpeter
Fred Mills (politician) (born 1955), Louisiana politician
REBEL (chess). REBEL is a world champion chess program developed by Ed Schröder. Development of REBEL started in 1980 on a TRS-80, and it was ported many times to dedicated hardware and the fastest microprocessors of the day:
1980s – Running on a TRS-80, Apple II, and inside of Mephisto brand dedicated chess computers, it won the Dutch open computer chess championship four times.
1991 – Ported to the ARM ChessMachine and named Gideon, it won the World Microcomputer Chess Championship.
1992 – Gideon won the World Computer Chess Championship, the first time a microprocessor came ahead of a field of mainframes, supercomputers, and custom chess hardware.
1990s – REBEL was ported to MS-DOS and then Microsoft Windows and sold commercially
1997 – REBEL won a match with GM Arthur Yusupov 10.5–6.5, the first successful challenge of a chess grandmaster by a commercial program.
1998 – REBEL won a match with GM Viswanathan Anand 5–3 (but lost 0.5–1.5 in the standard time control section of the match).  He was rated number two in the world at the time.
2004 – Ed Schröder retired, releasing the last version of REBEL as the freeware chess engine Pro Deo.
2022 - On January 12, 2022, Ed Schröder came out of retirement to release REBEL 14 as a free chess engine. It incorporates an efficiently updatable neural network in REBEL's evaluation function, along with a heavily modified version of Fruit's search.

See also
 Fruit (software)

References

External links
 
 
 
Rebel (Chess Programming Wiki)

Chess engines
Mathematica (disambiguation). Wolfram Mathematica is a computer algebra system and programming language.

Mathematica may also refer to:
Mathematica Inc. (1968–1986), a defunct research and software company
 Mathematica Inc., a policy research organization spun-off from the above company, formerly known as Mathematica Policy Research
Philosophiæ Naturalis Principia Mathematica, Newton's book on the basic laws of physics
Mathematica: A World of Numbers... and Beyond, interactive mathematics exhibit (1961) designed by Charles and Ray Eames
Principia Mathematica, Whitehead and Russell's work on axiomatizing mathematics

See also
Mathematics (disambiguation)
Short Satellite. The Short S.4 Satellite was a small British two-seater sporting monoplane, produced in 1924 to take part in the Air Ministry's Two-Seater Light Aeroplane competition on 27 September of that year.

Design
Design began in July, with only weeks available before the competition, so the monocoque fuselage was of conventional design, with wooden box spars; the ribs however were of duralumin, as were the tailplane, elevators, fin and rudder.
The cantilever wings had a span of 34 ft (10.3 m) and they, the tail and the fuselage were fabric-covered. The Satellite was fitted initially with an ungeared Bristol Cherub engine, with which it had a top speed of  without a passenger.

History
The aircraft was initially fitted with an ungeared Bristol Cherub engine at the Air Ministry's Two-Seater Light Aeroplane competition at Lympne in 1924, where the Satellite was flown by the company's chief test pilot J. Lankester Parker. The engine delivered insufficient power to fly with a passenger, so the Satellite, along with nine of the other 18 entrants, failed to meet the competition's success criteria. It was fitted with a tuned version of the Cherub within the week and on 4 October took part in the Grosvenor Cup race, completing the course and finishing in seventh place. It was later fitted with a geared Cherub II, later still with an ABC Motors Scorpion Mk. II engine, both of which greatly improved its performance. As a result of violent wing flutter experienced at , the wingspan was reduced by ; this solved the problem and no flutter was experienced even at dives of up to 120 mph.

The Satellite was sometimes irreverently referred to as "Parker's Tin Kettle" because he frequently flew the aircraft.

Specifications

Notes

References 

 
 "The Guild of Aircraft Pilots and Navigators of London 1929 - 2004"
 

1920s British sport aircraft
Short Brothers aircraft
Single-engined tractor aircraft
Mid-wing aircraft
Aircraft first flown in 1924
Rubinius. Rubinius is an alternative Ruby implementation created by Evan Phoenix. Based loosely on the Smalltalk-80 Blue Book design, Rubinius seeks to
"provide a rich, high-performance environment for running Ruby code."

Goals
Rubinius follows in the Lisp and Smalltalk traditions, by natively implementing as much of Ruby as possible in Ruby code.

It also has a goal of being thread-safe in order to be able to embed more than one interpreter in a single application.

Sponsorship 
From 2007 to 2013, Engine Yard funded one full-time engineer to work exclusively on Rubinius. Evan Phoenix now works at HashiCorp.

PowerPC64 support 
Since version 2.4.0, support on PowerPC64 is enabled.

See also

 Jikes RVM
 JRuby
 MacRuby
MagLev
 Parrot virtual machine
 PyPy
 Squawk
 Squeak
 YARV

References

External links
 
 Evan Phoenix's Blog
 Evan Phoenix's video at RubyConf 2007
 Evan Phoenix's video at MountainWest RubyConf 2008
 Evan Phoenix's presentation at RubyConf 2008
 
 The Great Ruby Shootout (December 2008): Rubinius compared to other common Ruby VMs
 
 Is It Rubinius?- Community-powered gem compatibility for Rubinius

Beta software
Free and open source interpreters
Free software programmed in C++
Free software programmed in Ruby
Ruby (programming language)
CCNI. CCNI may refer to:
Computational Center for Nanotechnology Innovations, supercomputing centre at the Rensselaer Polytechnic Institute, USA
Charity Commission for Northern Ireland, government body regulating charities in Northern Ireland
CCNI (gene), also known as Cyclin 1
 CCNI S.A., Compañía Chilena de Navegación Interoceánica S.A. (Chilean Interoceanic navigation company)
Comité consultatif national de l'immunisation (CCNI), French name of the National Advisory Committee on Immunization (NACI) of Canada
List of mathematic operators. In mathematics, an operator or transform is a function from one space of functions to another. Operators occur commonly in engineering, physics and mathematics. Many are integral operators and differential operators.

In the following L is an operator

which takes a function  to another function . Here,  and  are some unspecified function spaces, such as Hardy space, Lp space, Sobolev space, or, more vaguely, the space of holomorphic functions.

See also
 List of transforms
 List of Fourier-related transforms
 Transfer operator
 Fredholm operator
 Borel transform
 Glossary of mathematical symbols

Operators
Operators
Operators
Tunisian Air Force. The Tunisian Air Force (, ) is one of the branches of the Tunisian Armed Forces.

History
The Tunisian Air Force was established in 1959, three years after Tunisia regained its independence from France.  It took deliveries of its first aircraft, eight Saab 91 Safirs, in 1960, later to be complemented by further Saab 91 Safirs. The Tunisian Air Force entered the jet age in 1965 with the purchase of 8 MB326-Bs and then 5 MB326-LTs. In 1969, the country received 15 ex-USAF F-86F Sabres. Between 1974 and 1978 12 SF.260 Warriors and 9 SF.260Cs were delivered for basic training. In 1977–78, eight MB.326KTs were supplied for light attack duties. In 1981, Tunisia ordered 12 F-5s (8 F-5E and 4 F-5F); deliveries took place in 1984–85. Tunisia added 5 ex-USAF F-5Es from the Alconbury Aggressor Squadron in 1989. In 1985 Tunisia ordered two C130-H Herculeses. In 1995, a major Czech order was placed, with 12 Aero L-59 armed trainers and 3 Let L-410UVP transports ordered. In 1997, five surplus C-130B's were delivered from the USA. Tunisia had two C-130J-30s on order for delivery in 2013 and 2014. Tunisia purchased a 8 UH-60M.

Tunisia's four main bases are Bizerte/Sidi Ahmed, Gafsa, Bizerte/La Karouba, and Sfax.

Organization
The order of battle of the Tunisian Air force is as below:

Tunis-Laouina
No. 12 Squadron Transport squadron, Let L-410 Turbolet

Bizerte-Sidi Ahmed
No. 11 Squadron Jet trainer squadron, Aermacchi MB-326 
No. 15 Squadron Fighter squadron, Northrop F-5 Tiger 
No. 21 Squadron Transport squadron, C-130 Hercules, G-222

Bizerte-La Karouba
No. 31 Squadron Helicopter squadron, Bell 205, UH-1 Iroquois
No. 32 Squadron Helicopter squadron, Alouette II, Ecureuil
No. 33 Squadron Helicopter squadron
No. 36 Squadron Helicopter squadron

Sfax-Thyna
No. 13 Squadron Light utility and liaison squadron, flying SF-260s
No. 14 Squadron Light utility and liaison squadron, flying SF-260s
No. 31 Squadron Helicopter squadron

Gafsa
No. 16 Squadron Jet trainer squadron, flying L-59s
No. 34 Squadron

Aircraft

Current inventory

References

Sources

 World Aircraft Information Files. Brightstar Publishing, London. File 337 Sheet 03

Air forces by country
Military of Tunisia
Military units and formations established in 1959
1959 establishments in Tunisia
Military aviation in Africa
Time-sharing system evolution. This article covers the evolution of time-sharing systems, providing links to major early time-sharing operating systems, showing their subsequent evolution.

The meaning of the term time-sharing has shifted from its original usage. From 1949 to 1960, time-sharing was used to refer to multiprogramming; it evolved to mean multi-user interactive computing.

Time-sharing

Time-sharing was first proposed in the mid- to late-1950s and first implemented in the early 1960s. The concept was born out of the realization that a single expensive computer could be efficiently utilized by enabling multiprogramming, and, later, by allowing multiple users simultaneous interactive access. In 1984, Christopher Strachey wrote he considered the change in the meaning of the term time-sharing to be a source of confusion and not what he meant when he wrote his original paper in 1959.

Without time-sharing, an individual user would enter bursts of information followed by long pauses; but with a group of users working at the same time, the pauses of one user would be filled by the activity of the others. Similarly, small slices of time spent waiting for disk, tape, or network input could be granted to other users. Given an optimal group size, the overall process could be very efficient.

Each user would use their own computer terminal, initially electromechanical teleprinters such as the Teletype Model 33 ASR or the Friden Flexowriter; from about 1970 these were progressively superseded by CRT-based units such as the DEC VT05, Datapoint 2200 and Lear Siegler ADM-3A.

Terminals were initially linked to a nearby computer via current loop or serial cables, by conventional telegraph circuits provided by PTTs and over specialist digital leased lines such T1. Modems such as the Bell 103 and successors, allowed remote and higher-speed use over the analogue voice telephone network.

Family tree of major systems
See details and additional systems in the table below. Relationships shown here are for the purpose of grouping entries and do not reflect all influences. The Cambridge Multiple-Access System was the first time-sharing system developed outside the United States.

System descriptions and relationships

See also
History of CP/CMS has many period details and sources.
Timeline of operating systems

Notes

References

History of software
 Time-sharing system evolution
Fairey Hamble Baby. The Fairey Hamble Baby was a British single-seat naval patrol floatplane designed and built by Fairey Aviation for the Royal Naval Air Service

Design and development
Fairey Aviation built a number of Sopwith Baby floatplanes at its Hamble works. A variant of the Sopwith Baby was built by the Fairey Aviation Co., Ltd. On 23 October 1916, Sopwith Baby No.8134 was sent to the Fairey works for repair, and the opportunity was taken to rebuild the aircraft to incorporate a number of modifications. The most significant was the Fairey Patent Camber Gear, which was a form of trailing edge flap used to increase lift. On the Fairey-built aircraft, the entire trailing edge of each wing was hinged along the rear spar, lowered by rotating a handwheel in the cockpit. A differential device ensured that the flaps could still be actuated as ailerons; thus, lateral control was maintained. In this modified form, the aircraft was known as the Fairey Hamble Baby. Production Hamble Babies differed in appearance from those built by Sopwith and Blackburn. The planform of wings and tailplane were changed: the wings had increased span and reduced chord, had rounded tips, and the tailplane had a characteristic shape different from the semi-circular outline of the Sopwith original. A new and angular fin, Fairey-designed main floats of new form, and an enlarged tail float were fitted, and the engine cowling was modified. Parnall also produced Hamble Babies, which had some detail differences from the Fairey produced aircraft. The last 74 aircraft were produced by Parnall as landplanes and known as the Hamble Baby Convert.

Operators

Hellenic Navy

Royal Air Force
No. 219 Squadron RAF
No. 225 Squadron RAF
No. 229 Squadron RAF
No. 249 Squadron RAF
No. 253 Squadron RAF
No. 263 Squadron RAF
Royal Naval Air Service

Specifications (110 hp Clerget)

See also

References

Notes

Bibliography

 
 

Floatplanes
Hamble Baby
Biplanes
Single-engined tractor aircraft
Rotary-engined aircraft