omniomni/omni-engineering huggingface dataset:
Apple ProFile. The ProFile (codenamed Pippin) is the first hard disk drive produced by Apple Computer, initially for use with the Apple III. The original model had a formatted capacity of 5 MB and connected to a special interface card that plugged into an Apple III slot. In 1983, Apple offered a ProFile interface card for the Apple II, with software support for Apple ProDOS and Apple Pascal.

Additionally, in 1983, Apple introduced the Lisa computer, which was normally sold with a ProFile. The ProFile could be connected to the built-in parallel port of the Lisa, or to a port on an optional dual-port parallel interface card. Up to three such interface cards could be installed, so in principle up to seven ProFile drives could be used on a Lisa.

The 5 MB ProFile was Apple's first hard drive, and was introduced in September 1981 at a price of . Later, a 10 MB model was offered, but required an upgraded PROM/interface card to recognize the additional 5 MB.

Internally, the ProFile consisted of a bare Seagate ST-506 stepper motor drive and mechanism, without the usual Seagate electronics, a digital and an analog circuit board designed and manufactured by Apple, and a power supply.

Later Lisa models could be configured with an internal 10 MB "Widget" voice-coil drive with a proprietary controller designed and built entirely by Apple, but the Widget was never offered as an external product for use with other Apple computers.

Apple did not offer another hard drive until it released the Hard Disk 20 designed specifically for the Macintosh 512K in September 1985 which could not be used on the Apple II or III families, or Lisa series. The ProFile could not be used on the Macintosh or the Apple IIc (for which Apple never offered an external hard disk drive of any kind).

By September 1986, the ProFile would be superseded by the introduction of the first cross-platform Hard Disk 20SC SCSI-based drive for the Macintosh and interface card for the Apple II family (excluding the IIc series, which had no SCSI interface of any kind) and Lisa/XL series.

References

ProFile
Apple II peripherals
Apple Inc. peripherals
Hard disk drives
Computer-related introductions in 1981
CUDI. The University Corporation for Internet Development (; CUDI) is a non-profit consortium to build and operate a Mexican high-performance backbone network for research and education, sometimes called Internet-2 for Mexico.

Overview

Established in 2000, the RedCUDI (CUDI Network) backbone had, during many years, a capacity of 155 Megabits per second (STM-1) using ATM, recently 10 Gigabits links, with 3 international links to Abilene Network, Gigabit links to the California Research and Education Network (CalREN) managed by CENIC, and one Mbit link to RedCLARA. Over 200 members institutions (research centers, universities) participate in RedCUDI, some corporate and affiliate institutions, in all of the 31 states of Mexico. Its purpose has been to develop and deploy advanced network applications and technologies such as IPv6, IP multicasting, quality of service, Software-defined networking  and other innovations.

References

External links
 Home of CUDI

National research and education networks
Universities and colleges in Mexico
Boeing New Large Airplane. The Boeing NLA, or New Large Airplane, was a 1990s concept for an all-new quadjet airliner in the 500+ seat market. With a proposed size somewhat larger than the 747, it was a similar concept to the McDonnell Douglas MD-12 and later Airbus A380. In 1993, Boeing chose not to pursue development of this concept, focusing instead on the Boeing 747-500X and -600X, and then on the 747X and 747X Stretch, and subsequently on the Boeing 747-8. The project names for this proposal were NLA and Boeing 763-246C.

History
The Boeing New Large Airplane was one of several projects proposed by Boeing in the late 20th century as ways to compete with its rival Airbus. The Airbus A380 project began to be publicized in 1990 in order to try and turn the commercial aviation market away from the then very prevalent Boeing 747. Boeing sought to combat this and began working up designs for the NLA in the early 1990s, with a projected service entry date of before 2000 in order to beat the Airbus A380.

The goal of the NLA project was to create an airplane capable of traveling primarily long-haul routes and carrying vast amounts of passengers or cargo. At the time of design, ETOPS had not been introduced, and twinjet aircraft were not considered suitable for transpacific flights, so the NLA was designed with a four-jet layout (two on each wing), much like the 747 and the A380. It was designed to fly long-haul, high-demand flights such as Sydney to Dubai or London to New York, taking from 8 to 14 hours. With the goal of beating its competitors based on sheer passenger volume, the NLA design was to have included a full-length two deck configuration. This would have allowed for 600–1000 passengers (depending on airline and class seating configurations), about 50 more passengers than the A380 per configuration.

However, after only a few years of working on the project, Boeing decided that the NLA model was unsustainable with the way the commercial aviation market was trending. Instead of larger, higher capacity aircraft with the ability to make long hub-to-hub routes in a single go, Boeing decided the future was in smaller, more direct flights. As a result, they cancelled the NLA project.

Specifications (NLA, as designed)

Source: Seattle Post-Intelligencer

See also

References

Abandoned civil aircraft projects of the United States
NLA
Quadjets
Joseph Francis Joy. Joseph Francis Joy (September 13, 1883 – February 1957) was born in the small mining town of Cumberland, Maryland.  Joy is known for being an inventor.  He accumulated 190 patents in his lifetime.

His major inventions were the first continuous mining machines recognized as milestones in the history of underground mining mechanization. He had pioneered new concepts in hydraulics, modern control and power circuits, trackless mining equipment, efficient gearing and seal designs as well as dozens of other "firsts" in the industry. His mining machines changed forever the way minerals are mined  dramatically improving production. Many of his machines are still in use today.  

Joy is also known for founding the company that bears his name in Franklin Pennsylvania: Joy Mining Machinery.

Notes

External links 
Joy Mining Machinery History
Joy Manufacturing Company records (1915-1989) at Hagley Museum and Library

1883 births
1957 deaths
American mining engineers
People from Cumberland, Maryland
20th-century American inventors
GMD. GMD may refer to:

 Ben Slimane Airport, in Morocco
 Gambian dalasi, the currency of Gambia by ISO 4217 code
 Game (retailer), a British video game retailer
 GDP-mannose 4,6-dehydratase, in enzymology 
 General material designation, in library cataloguing 
 General Motors Diesel, a Canadian diesel locomotive manufacturer
 Generalmusikdirektor (general music director) for an orchestra, town etc. 
 Geoscientific Model Development, a journal
  (Society for Mathematics and Information technology), now a part of the Fraunhofer Society
 Gibraltar Medallion of Distinction
 The Glam Metal Detectives, a British comedy series
 Goldstein Museum of Design of the University of Minnesota
 Golm Metabolome Database, in chemical processes 
 Grimsby Docks railway station, in England
 Ground-Based Midcourse Defense, part of the United States missile defense system
 Kuomintang, a major Taiwanese political party (based on alternative pinyin romanization of "Guomindang") 
 Maghdi language, spoken in Nigeria
Ravi Arimilli. Ravi Arimilli (born 1963) is an IBM Fellow and Chief Architect. Largely responsible for development of the POWER5, he is one of the most prolific inventors in the world, being awarded 78 patents in 2002 and a further 53 in 2003. He has over 507 patents to his name and is listed among the most prolific inventors in the world as measured by U.S. utility patents.

Arimilli moved with his family to the United States from Andhra Pradesh, India, in 1969. He studied at Louisiana State University, and joined IBM in 1985. His expertise includes symmetric multiprocessing (SMP) system structures, cache/memory hierarchies and system bus protocols.

References

External links
The Times of India article on Arimilli
A news item about Arimilli on rediff.com

1963 births
Living people
IBM employees
IBM Fellows
Telugu people
Crystal Reports. Crystal Reports is a business intelligence application marketed to small- and medium-sized businesses by SAP.

History
Terry Cunningham and the Cunningham Group originated the software in 1984.  Crystal Services Inc. marketed the product (originally called "Quik Reports") when they could not find a suitable commercial report writer for an accounting software they developed add-on products for, which was ACCPAC Plus for DOS (later acquired by Sage).  After producing versions 1.0 through 3.0, Crystal Services was acquired by Seagate Technology in 1994. Crystal Services was combined with Holistic Systems to form the Information Management Group of Seagate Software, which later rebranded as Crystal Decisions and produced versions 4.0 through 9.0. Crystal Decisions was acquired in December 2003 by BusinessObjects, which produced versions 10, 11 (XI) and version 12 (2008).

SAP acquired BusinessObjects on October 8, 2007, and released Crystal Reports 2011 (version 14) on May 3, 2011. The latest version released is Crystal Reports 2020 (14.3.x) on June 13, 2020.

The file extension for Crystal Reports' proprietary file format is .rpt. The design file can be saved without data, or with data for later viewing or sharing. Introduced with the release of Crystal Reports 2011 (version 14.0), the read-only .rptr file extension option allows for viewing, but cannot be modified once exported.

Several other applications, including Microsoft Visual Studio versions 2003 through 2008, and Borland Delphi, at one time bundled an OEM version of Crystal Reports as a general purpose reporting tool.  Microsoft discontinued this practice and later released their own competing reporting tool, SQL Server Reporting Services (SSRS).

Versions and editions

 A=Advanced Developer, D=Developer, P=Professional, S=Standard

See also
 Dashboard (business)
 List of reporting software
 Jasper Reports

References

Bibliography

External links
 
 SAP.com Product Page

Reporting software
Hunt-class mine countermeasures vessel. The Hunt class is a class of thirteen mine countermeasure vessels of the Royal Navy. As built, they combined the separate roles of the traditional minesweeper and that of the active minehunter in one hull, but later modifications saw the removal of mine-sweeping equipment. They have a secondary role as offshore patrol vessels.

Development
Upon introduction in the early 1980s they were the largest warships ever built out of glass-reinforced plastic and were the last in operation to use the Napier Deltic diesel engine. All were built by Vosper Thornycroft in Woolston except  and , which were built by Yarrow Shipbuilders Limited on the River Clyde.  was the last ship of the class launched. 

Following the sale of  and  to the Greek Navy, the sale of  and  to the Lithuanian Navy and the decommissioning of , a contract to re-engine the remaining eight vessels was signed by BAE Systems in 2008, whereby the existing 30-year old Napier Deltic 9-59K power units were replaced by Caterpillar CAT C32 engines, together with new gearboxes, bow thrusters, propellers and control systems, in a six year refurbishment programme that was completed in 2018.

The capabilities of the remaining eight vessels of the Hunt class have been significantly enhanced by the installation of Sonar Type 2193 and the NAUTIS 3 command system. The performance of Sonar 2193 exceeds that of any other mine hunting sonar in service in the world today and is capable of detecting and classifying an object the size of a football at a distance of up to . In late 2007 Chiddingfold  used the Seafox drone, the Royal Navy's mine disposal system, during Exercise Neptune Warrior off Scotland. Seafox is described by the MOD as a "state of the art fire and forget system, capable of destroying mines in depths of up to 300 metres".

The 2021 defence white paper announced that all the Hunt-class vessels would be retired from Royal Navy service in the 2020s and replaced by automated systems. It was subsequently indicated that the withdrawal would occur in the 2029 to 2031 period.

In 2023, the navy began to take delivery of six REMUS 300 small autonomous underwater vehicles (SAUVs), produced by Huntington Ingalls Industries. The system is being acquired to enhance the capabilities of the Hunt-class ships and has a reported operating depth of 300 meters with an endurance time of up to 20 hours.

Ships in the class
All 13 ships of this class re-used names from the World War II . Four of the names had also been used for World War I s: these were HMS Bicester, Cattistock, Cottesmore and Quorn.  had been a paddlewheel minesweeper in 1916, and  was a coaster taken up from trade in 1916.

See also
Sandown-class minehunter

References

External links

Patrol vessels of the United Kingdom
 
Mine warfare vessel classes
Napier Deltic
Ship classes of the Royal Navy
Donald Bailey (civil engineer). Sir Donald Coleman Bailey, OBE (15 September 1901 – 5 May 1985) was an English civil engineer who invented the Bailey bridge.  Field Marshal Montgomery is recorded as saying that "without the Bailey bridge, we should not have won the war."

Background 
Bailey attended Rotherham Grammar School and The Leys School in Cambridge. He read for a BEng degree at the University of Sheffield and graduated in 1923.

Bailey was a civil servant in the War Office when he designed his bridge. Another engineer, A. M. Hamilton, successfully demonstrated that the Bailey bridge breached a patent on the Callender-Hamilton bridge, though the Bailey bridge was generally regarded as being superior for temporary use. Because the bridge used a pin joining system similar to that used in the Martel Bridge designed by Lt.-General Sir Giffard Le Quesne Martel, Hamilton also told the commission the Bailey bridge should be called a 'Martel Mk2', and Martel was later awarded £500 for infringement on the design of his box girder bridge.

Bailey was knighted in 1946 for his bridge design. By this time he was living quietly in Southbourne in Bournemouth. Dorothy Barnes, one of the girls at the Southbourne Crossroads bank, which he used regularly was surprised to learn that her unassuming customer had been knighted. He died in Bournemouth in 1985.  There is, as yet, no blue plaque in Bournemouth to commemorate him. His 1940s home was demolished c 2004 and replaced by flats, although he also had other addresses in Bournemouth, being recorded in 1974 at 14 Viking Close, as Bailey, Sir Donald C. OBE, JP. The house in which Bailey was born, 24 Albany Street, Rotherham is still standing.

During the Second World War, there was a factory making the components for the Bailey bridge in the neighbouring town of Christchurch, where a section of bridge still remains, at a retail park in Barrack Road. The components were shipped to training grounds in Cumbria, where men learned the difficult technique of assembling them in rivers at night, to simulate combat conditions.

Field Marshal Bernard Montgomery wrote in 1947:

Honours and awards
4 January 1943 - Officer of the Order of the British Empire (OBE) for Donald Coleman Bailey, Esq., O.B.E., A.M.Inst.C.E., Assistant Superintendent and Chief Designer, Experimental Bridging Establishment, Ministry of Supply.
1 January 1946 - Knighthood for Donald Coleman Bailey, Esq., O.B.E., A.M.Inst.C.E., Acting Superintendent, Experimental Bridging Establishment, Ministry of Supply.
1 January 1948 - Commander of the Order of Orange-Nassau for services during the war.

References

External links
 Pathe News, newsreel featuring Balie, 1945.

Gallery

English civil engineers
Alumni of the University of Sheffield
Civil servants in the War Office
People educated at The Leys School
English inventors
People from Rotherham
War Office personnel in World War II
Knights Bachelor
Officers of the Order of the British Empire
Commanders of the Order of Orange-Nassau
1901 births
1985 deaths
Civil servants in the Ministry of Supply
Svensk Lufttrafik. Svensk Luftrafik (SLA, SLAB, Svenska Lufttrafikbolaget) was a Swedish airline based in Stockholm.  The company was founded on 7 February 1919, its first flight running on the 7 August 1920. Flight operations of the company were terminated in 1921, 

SLAB operated air-mail services in co-operation with Deutsche Luft-Reederei, a Lufthansa precursor, and operated a regular passenger service Copenhagen–Malmö–Warnemünde. In 1921 the company built the Lindarängen seaplane airport (Lindarängens flyghamn) in Stockholm and started regular services to Reval, (later known as Tallinn, capital of Estonia) with a Junkers F.13 and two Savoia S-16 flying boats. The fleet also included 10 LVG C.VI aircraft from the German Luftverkehrsgesellschaft, of which only two remained airworthy after the liquidation of the company.

Lindarängen airport was sold to the City of Stockholm after the dissolution of Svensk Luftrafik in 1923 and remained in operation until 1952.

During the first half of 1920, the later German Nazi-Leader Hermann Göring was employed as a pilot with the company and on February 21, flew Count Eric von Rosen to his estate Rockelstad where Göring met his first wife, the Swedish national Carin von Kantzow.

Notes / References 

 This article is based on the entry of the Swedish version of Wikipedia, which may offer further references.

Defunct airlines of Sweden
Transport in Malmö
Airlines established in 1919
Airlines disestablished in 1921
Fusibility. The fusibility of a material refers to the ease at which the material can be fused together, or to the temperature or amount of heat required to melt a material.
Materials such as solder require a relatively low melting point so that when heat is applied to a joint, the solder will melt before the materials being soldered together melt, i.e. high fusibility. On the other hand, firebricks used for furnace linings only melt at very high temperatures (and then they retract, or decompose, or become fracture-prone) and so have low fusibility. Perhaps refractory materials often have low fusibility.

Scientific methods

To find the fusibility of certain compounds/materials, there are 2 methods:

Heat test

The most common test used to determine fusibility is to join two pieces with a variable heat source, increasing the temperature or power used in steps, and testing bond strength for each step. If there is no step with good bond strength after joining, then fusibility is said to be low.

Ash fusibility test

In the context of coal analysis, ash fusibility values of the residual coal ash of a coal are often specified.  The values are determined using an empirical method based on the geometrical changes upon heating to a relevant temperature, of a conical ash sample.  The fusibility of the ash is of interest because it roughly indicates the properties of the clinker that will be produced during burning.

References

Chemical properties
Hard spheres. Hard spheres are widely used as model particles in the statistical mechanical theory of fluids and solids. They are defined simply as impenetrable spheres that cannot overlap in space. They mimic the extremely strong ("infinitely elastic bouncing") repulsion that atoms and spherical molecules experience at very close distances. Hard spheres systems are studied by analytical means, by molecular dynamics simulations, and by the experimental study of certain colloidal model systems.

Beside being a model of theoretical significance, the hard-sphere system is used as a basis in the formulation of several modern, predictive Equations of State for real fluids through the SAFT approach, and models for transport properties in gases through Chapman-Enskog Theory.

Formal definition

Hard spheres of diameter  are particles with the following pairwise interaction potential:

where  and  are the positions of the two particles.

Hard-spheres gas

The first three virial coefficients for hard spheres can be determined analytically

{|
|||=|| 
|-
|||=||  
|-
|||=||  
|}

Higher-order ones can be determined numerically using Monte Carlo integration. We list

{|
|||=|| 
|-
|||=|| 
|-
|||=|| 
|}
A table of virial coefficients for up to eight dimensions can be found on the page Hard sphere: virial coefficients.

The hard sphere system exhibits a fluid-solid phase transition between the volume fractions of freezing  and melting . The pressure diverges at random close packing  for the metastable liquid branch and at close packing  for the stable solid branch.

Hard-spheres liquid

The static structure factor of the hard-spheres liquid can be calculated using the Percus–Yevick approximation.

The Carnahan-Starling Equation of State 
A simple, yet popular equation of state describing systems of pure hard spheres was developed in 1969 by N. F. Carnahan and K. E. Starling. By expressing the compressibility of a hard-sphere system as a geometric series, the expression

is obtained, where  is the packing fraction, given by

where  is Avogadros number,  is the molar density of the fluid, and  is the diameter of the hard-spheres. From this Equation of State, one can obtain the residual Helmholtz energy,

,

which yields the residual chemical potential

.

One can also obtain the value of the radial distribution function, , evaluated at the surface of a sphere,

.

The latter is of significant importance to accurate descriptions of more advanced intermolecular potentials based on perturbation theory, such as SAFT, where a system of hard spheres is taken as a reference system, and the complete pair-potential is described by perturbations to the underlying hard-sphere system. Computation of the transport properties of hard-sphere gases at moderate densities using Revised Enskog Theory also relies on an accurate value for , and the Carnahan-Starling Equation of State has been used for this purpose to large success.

See also 
Classical fluid

Literature

J. P. Hansen and I. R. McDonald Theory of Simple Liquids Academic Press, London (1986)
Hard sphere model page on SklogWiki.

References

Statistical mechanics
Conceptual models
Maintenance mode. The meaning of maintenance mode depends on the context.

In the world of software development, it refers to a point in a computer program's life when it has reached all of its goals and is generally considered to be "complete" and bug-free. The term can also refer to the point in a software product's evolution when it is no longer competitive with other products or current with regard to the technology environment it operates within. In both cases, continued development is deemed unnecessary or ill-advised, but occasional bug fixes and security patches are still issued, hence the term maintenance mode.  Maintenance mode often transitions to abandonware.

In the world of software maintenance, it refers to the operational mode a device or service may enter when it is being maintained. For example, while diagnosing, reconfiguring, repairing, upgrading or testing it may be necessary for the device or service to drop to maintenance mode until its fitness for operational mode is verified. Another use case is deliberately putting the device or service into maintenance mode so that it cannot be used operationally while being maintained.

Sometimes, when a popular free software project undergoes a major overhaul, the pre-overhaul version is kept active and put into maintenance mode because it will still be widely used in production for the foreseeable future. Project forks can also spawn from programs that go into maintenance mode too soon or have enough developer support for a more advanced version. A good example of this is the vi editor, which was in maintenance mode and forked into Vi IMproved. The Vim fork has many useful features that vi does not, such as syntax highlighting and the ability to have multiple open buffers.

See also
 Steady state

References

Software maintenance