omniomni/omni-engineering huggingface dataset:
Rollason Beta. The Rollason Beta was a British midget racing monoplane developed from a competition to build a Formula One air racer in the 1960s in England.  The Beta was first flown on 21 April 1967. The aircraft were successful air-racers in England during the late 1960s and early 1970s.

Development
The Beta was designed by the Luton Group (who were young technicians employed by the British Aircraft Corporation at Luton) in a competition to design a racing aircraft, the Rollason Midget Racer Design Competition 1964.

The Beta is a fully aerobatic wooden low-wing cantilever monoplane with a cantilever tailplane with a single fin and rudder, powered by a Continental engine of between 65 and 100 hp. It has a fixed-tailwheel landing gear and an enclosed cockpit for the pilot. The original prototype Luton Beta was not completed. The design was built commercially by Rollason Aircraft and Engines who made 4 aircraft at Redhill between 1967 and 1971. Plans were also available for homebuilding; although 55 sets of drawings had been sold by early 1974, five aircraft have been registered but just three aircraft are known to have been completed, all in the UK.

Operational history
The first Rollason-built Beta (registered G-ATLY and named Forerunner) won the Manx Air Derby in 1969 and the second Rollason-built aircraft (registered G-AWHV and named Blue Chip) won the Goodyear Trophy air race at Halfpenny Green in 1969.

G-ATLY was written off in an aerial collision with a Tiger Moth at Nottingham on 29 September 1973, killing the pilot, G-AWHV was destroyed by fire in 1995 and G-AWHW crashed on 17 December 1987 at RAF Wattisham, Suffolk, killing the pilot.

Variants

B.1
Powered by a 65hp Continental A65 engine, one built by Rollason later converted to B.2
B.2
Powered by a 90hp Continental C90 engine, one by Rollason and one conversion from B.1
B.2A
As B.2, but with steel sprung undercarriage, two built by Rollason
B.4
Powered by a 100hp Rolls-Royce Continental O-200-A engine, none built.

Specifications (Beta B.2)

References

Bibliography

 Flight International 19 October 1967

External links

 Rollason Beta – British Aircraft Directory

1960s British sport aircraft
Homebuilt aircraft
Single-engined tractor aircraft
Low-wing aircraft
Aircraft first flown in 1967
Design Exchange Format. Design Exchange Format (DEF) is an open specification for representing physical layout of an integrated circuit in an ASCII format. It represents the netlist and circuit layout. DEF is used in conjunction with Library Exchange Format (LEF) to represent complete physical layout of an  integrated circuit while it is being designed. 

DEF was developed by Cadence Design Systems.

DEF files are usually generated by place and route (P&R) tools and are used as an input for post analysis tools, such as extraction tools or power analysis tools.

External links
LEF/DEF 5.5 Language Reference, Product Version 5.5, Internet Archive
 
LEF/DEF 5.6 Language Reference from Cadence Design Systems, Internet Archive

LEF/DEF 5.7 Language Reference from cadence Design Systems, Internet Archive

LEF/DEF 5.8 Language Reference from cadence Design Systems, Internet Archive

EDA file formats
MAW. MAW may refer to:
 Malawi, a republic in southeast Africa
 Make-A-Wish Foundation, a U.S. charity
 Marine Aircraft Wing, the largest aviation unit in the United States Marine Corps
 Masters at Work, the house music producers "Little" Louie Vega and Kenny "Dope" González
 Men at Work, an Australian pop band
 Mexican–American War, between the U.S. and Mexico in 1846–1848
 Missile approach warning system, aircraft equipment to detect an approaching anti-aircraft missile
 Mission Adaptive Wing, Adaptive compliant wing for aircraft which can change form
 Modified Atlantic Water, water flowing from the Atlantic Ocean into the Mediterranean through the Alboran Sea

See also
 Maw (disambiguation)
Magnetic scalar potential. Magnetic scalar potential, ψ, is a quantity in classical electromagnetism analogous to electric potential.  It is used to specify the magnetic H-field in cases when there are no free currents, in a manner analogous to using the electric potential to determine the electric field in electrostatics. One important use of ψ is to determine the magnetic field due to permanent magnets when their magnetization is known. The potential is valid in any simply connected region with zero current density, thus if currents are confined to wires or surfaces, piecemeal solutions can be stitched together to provide a description of the magnetic field at all points in space.

Magnetic scalar potential 

The scalar potential is a useful quantity in describing the magnetic field, especially for permanent magnets.

Where there is no free current,

so if this holds in simply connected domain we can define a , , as

The dimension of  in SI base units is  which can be expressed in SI units as amperes.

Using the definition of :

it follows that

Here,  acts as the source for magnetic field, much like  acts as the source for electric field. So analogously to bound electric charge, the quantity

is called the bound magnetic charge density. Magnetic charges  never occur isolated as magnetic monopoles, but only within dipoles and in magnets with a total magnetic charge sum of zero. The energy of a localized magnetic charge  in a magnetic scalar potential is

and of a magnetic charge density distribution  in space

where  is the vacuum permeability. This is analog to the energy  of an electric charge  in an electric potential .

If there is free current, one may subtract the contributions of free current per Biot–Savart law from total magnetic field and solve the remainder with the scalar potential method.

See also 
 Magnetic vector potential

Notes

References 
 

 

Potentials
Magnetism
Torpedinidae. The family Torpedinidae contains 22 species of electric rays or torpedoes, flat cartilaginous fishes that produce electricity as a defense and feeding mechanism. They are slow-moving bottom-dwellers.

The largest species is the Atlantic torpedo, Tetronarce nobiliana, which can grow to a weight of  and deliver a 220-volt electric shock. Electric rays have patches of modified muscle cells called electroplaques that make up an electric organ. These generate an electric gradient, similar to the normal electric potential across most cell membranes, but amplified greatly by its concentration into a very small area. The electricity can be stored in the tissues, which act as a battery. The shock can be discharged in pulses. A ray can emit a shock into the body of a prey animal to stun it and make it easier to capture and eat, or into the body of a predator. Tissue from electric rays is often used in neurobiological research because of its unique properties.

Torpedo rays are flat like other rays, disc-shaped, with caudal fins that vary in length. Their mouths and gill slits are located on their undersides. Males have claspers near the base of the tail. Females are ovoviviparous, meaning they form eggs but do not lay them. The young emerge from the eggs within the body of the female, and she gives live birth. The young are called pups.

The naval weapon known as the torpedo was named after this genus, whose own name has the same Latin origin as the English word torpid, meaning "sluggish" or "lethargic", presumably the sensations one would feel after experiencing the ray's electric shock.

Species
There are 22 species in 2 genera:

 Genus Tetronarce T. N. Gill, 1862
Tetronarce californica Ayres, 1855 (Pacific electric ray)
Tetronarce cowleyi Ebert, D. L. Haas & M. R. de Carvalho, 2015 (Cowley's torpedo ray) 
Tetronarce fairchildi F. W. Hutton, 1872 (New Zealand torpedo)
Tetronarce formosa D. L. Haas & Ebert, 2006 (Taiwan torpedo)
Tetronarce macneilli Whitley, 1932 (Shorttail torpedo)
Tetronarce nobiliana Bonaparte, 1835 (Atlantic torpedo)
Tetronarce puelcha Lahille, 1926 (Argentine torpedo)
Tetronarce tokionis S. Tanaka (I), 1908 (Trapezoid torpedo)
Tetronarce tremens F. de Buen, 1959 (Chilean torpedo)
 Genus Torpedo Forsskål, 1775
Torpedo adenensis M. R. de Carvalho, Stehmann & Manilo, 2002 (Aden Gulf torpedo)
Torpedo alexandrinsis Mazhar, 1987 (Alexandrine torpedo)
Torpedo andersoni Bullis, 1962 (Florida torpedo)
Torpedo bauchotae Cadenat, Capapé & Desoutter, 1978 (Rosette torpedo)
Torpedo fuscomaculata W. K. H. Peters, 1855 (Black-spotted torpedo)
Torpedo mackayana Metzelaar, 1919 (Ringed torpedo)
Torpedo marmorata A. Risso, 1810 (Marbled electric ray)
Torpedo microdiscus Parin & Kotlyar, 1985 (Smalldisk torpedo)
Torpedo panthera Olfers, 1831 (Leopard torpedo)
Torpedo semipelagica Parin & Kotlyar, 1985 (Semipelagic torpedo)
Torpedo sinuspersici Olfers, 1831 (Variable torpedo or Gulf torpedo)
Torpedo suessii Steindachner, 1898
Torpedo torpedo (Linnaeus, 1758) (Common torpedo)

References

 
Torpediniformes
Live-bearing fish
Ray families
Taxa named by Charles Lucien Bonaparte
Projects and Development India Limited. Projects and Development India Limited (PDIL) is an Indian central public sector undertaking under the ownership of the Ministry of Chemicals and Fertilizers, Government of India.

History 
PDIL started as the technology wing of Fertilizer Corporation of India in 1951, emerged as a separate entity named FPDIL in 1978 after the restructuring of Fertilizer Corporation of India and was renamed PDIL in 1981 with a head office in Sindri, Jharkhand. It is a project management and engineering consultancy providing services from concept to commissioning for fertilizer and allied chemical, oil and gas industries.

References

External links
 

Chemical companies of India
Oil and gas companies of India
Government-owned companies of India
Companies based in Noida
Non-renewable resource companies established in 1978
1978 establishments in Uttar Pradesh
Indian companies established in 1978
Shared Whois Project. The Shared Whois Project (SWIP) is the process used to submit, maintain and update information to ensure up-to-date and efficient maintenance of WHOIS records, as structured in RFC 1491. The process updates WHOIS to contain information regarding what organization is using a specific IP address, or a specific block of addresses. Additionally, it provides means to track the use of an organization's current allocations of IP addresses, so that additional allocation of IP addresses may be justified and usage reports or case studies may be done.

SWIP must be used within seven days of any reassignment of an IP address space to a downstream customer to:
 Provide new reassignments of blocks of eight or more IP addresses
 Delete existing reassignments, or
 Modify data connected to existing reassignments.

In contrast, an organization is not required to submit a SWIP template for fewer than eight IP addresses. 

Allocations, assignments or reassignments of blocks of 8,192 addresses and more (greater than a /19 block) must be approved by ARIN beforehand.  Companies assigned a block of 65,536 addresses or more will be responsible for maintaining all IN-ADDR.ARPA domain records for their customers.

There are two types of registration. The first is an allocation, for blocks of IP addresses which will later be reallocated or reassigned to third parties. The second is an assignment, for blocks that will not be reassigned, or the recipient is an end-user.

References

Bibliography

External links 
 ARIN's Reporting Reassignments
 

Internet protocols
Internet Standards
Fatal system error. A fatal system error (also known as a system crash, stop error, kernel error, or bug check) occurs when an operating system halts because it has reached a condition where it can no longer operate safely (i.e., where critical data could be lost or the system damaged in other ways).

In Microsoft Windows, a fatal system error can be deliberately caused from a kernel-mode driver with either the  or  function. However, this should only be done as a last option when a critical driver is corrupted and is impossible to recover. This design parallels that in OpenVMS. The Unix kernel panic concept is very similar.

In Windows 
When a bug check is issued, a crash dump file will be created if the system is configured to create them. This file contains a "snapshot" of useful low-level information about the system that can be used to debug the root cause of the problem and possibly other things in the background.

If the user has enabled it, the system will also write an entry to the system event log. The log entry contains information about the bug check (including the bug check code and its parameters) as well as a link that will report the bug and provide the user with prescriptive suggestions if the cause of the check is definitive and well-known.

Next, if a kernel debugger is connected and active when the bug check occurs, the system will break into the debugger where the cause of the crash can be investigated. If no debugger is attached, then a blue text screen is displayed that contains information about why the error occurred, which is commonly known as a blue screen or bug check screen.

The user will only see the blue screen if the system is not configured to automatically restart (which became the default setting in Windows XP SP2). Otherwise, it appears as though the system simply rebooted (though a blue screen may be visible briefly). In Windows, bug checks are only supported by the Windows NT kernel. The corresponding system routine in Windows 9x, named , does not halt the system like bug checks do. Instead, it displays the infamous "blue screen of death" (BSoD) and allows the user to attempt to continue.

The Windows DDK and the WinDbg documentation both have reference information about most bug checks. The WinDbg package is available as a free download and can be installed by most users. The Windows DDK is larger and more complicated to install.

See also
Screen of death
System crash

References

External links 
Debugging Tools for Windows at Microsoft Learn
Bug Check Code Reference at Microsoft Learn

Computer errors
Bower–Barff process. In metallurgy, the Bower–Barff process is a method of coating iron or steel with magnetic iron oxide, such as Fe2O4, in order to minimize atmospheric corrosion.

The articles to be treated are put into a closed retort and a current of superheated steam passed through for twenty minutes followed by a current of producer gas (carbon monoxide), to reduce any higher oxides that may have been formed.

References 
ebook of creative chemistry, page 273.

Metallurgical processes
Solarroller. Solarroller is a BEAM dragster photovore robot run by solar panel that utilizes sunlight. In competitions between solarrollers, each one must run one meter in the shortest time possible. Components include pager motors,
capacitors, resistors, transistors, and solar panels.

There are several different kinds of configurations of solarrollers, with bigger or smaller wheels, one or two motors. Configurations differences include: 
 motor (number and output),
 wheels (number and size), and 
 frame designs

This robot type always moves forwards. The motor drives one or more wheels. A "Solar Engine" circuit is used to feed the robot.
Solarroller's speed is directly related to the amount of light robot registers on its optical sensor. Most are driven by an electronic "relaxation oscillator", in which a charge is accumulated in a capacitor while at rest and then suddenly released in the drive mechanism.

See also
Mark Tilden

Further reading
 "Simple Solaroller". Electronics Now, June, 1997.
 Solarroller circuits. Mark Tilden's hand-written notes (c. 1990), solarbotics.net.
 Solarroller mechanics. Mark Tilden's hand-written notes (c. 1990), solarbotics.net.

External articles
 Solarbotics.net gallery of Solarrollers
 BEAM robotics Yahoo! group
 Beam-Online sollarrolers gallery with several different configurations
 2003 BEAM SolarRoller Race, robotgames.net
 Solarrollers on the BEAM Wiki

Solar car racing
Solar energy
BEAM robotics
Diskeeper. Diskeeper is a discontinued defragmentation app, designed for Microsoft Windows. It was developed by Executive Software International, Inc., which later changed its name to Diskeeper Corporation, and is now called Condusiv Technologies. The final version of Diskeeper was released in March 2020. All of Diskeeper's features and functionality are now included in Condusiv's data performance software DymaxIO.

History
Originally, Diskeeper was developed for the VAX series of minicomputers and later for Microsoft Windows. The defragmentation program which is included with Windows 2000, Windows XP and Windows Server 2003 is based on a basic version of Diskeeper. Diskeeper 9.0 (for Windows 2000 and XP) Server Edition introduced Terabyte Volume Engine (TVE), which provides optimal defragmentation performance on volumes of 1 TB and larger. Diskeeper 2008 Professional introduced a Volume Shadow Copy Service (VSS) compatibility mode, which defragments on a unit of 16 KB, so that VSS file history won't explode, invalidating cached old versions of the files.

Features
In addition to resolving file system fragmentation, Diskeeper also prevents fragmentation before it happens by optimizing the process of data being written to disk. Diskeeper can also defragment files on-the-fly, using only idle system resources as needed.

Another feature in Diskeeper is I-FAAST, or Intelligent File Access Acceleration Sequencing Technology. I-FAAST determines the frequency of file usage and the most frequently used files are then moved to the best portion of the disc. According to Diskeeper, this results in faster file access and also helps prevent future fragmentation of those files.  The I-FAAST feature is available in Professional, Pro Premier and Server editions.

There were six versions available: Home, Professional, Pro Premier, HomeServer, Server, and EnterpriseServer. Diskeeper Administrator is also available to manage Diskeeper options as well as perform advanced installations. Version 10 was the last version available for Windows 9x. After version 10, Diskeeper versions followed the year based naming convention, that is, 2007, 2008 and so on.

Critical reception
Diskeeper 2009 won Editor's Best Gold Award and Community's Choice Bronze Award for best system utility of 2009 from Windows IT Pro. Diskeeper 2010 however, only managed to achieve Editor's Best Bronze Award for best system utility of 2010.

See also
 Comparison of defragmentation software
 List of defragmentation software

References

Further reading

External links 
 

Windows-only trialware
Defragmentation software
Discontinued software
STONITH. STONITH ("Shoot The Other Node In The Head" or "Shoot The Offending Node In The Head"), sometimes called STOMITH ("Shoot The Other Member/Machine In The Head"), is a technique for fencing in computer clusters.

Fencing is the isolation of a failed node so that it does not cause disruption to a computer cluster. As its name suggests, STONITH fences failed nodes by resetting or powering down the failed node.

Multi-node error-prone contention in a cluster can have catastrophic results, such as if both nodes try writing to a shared storage resource. STONITH provides effective, if rather drastic, protection against these problems.

Single node systems use a comparable mechanism called a watchdog timer. A watchdog timer will reset the node if the node does not tell the watchdog circuit that it is operating well. A STONITH decision can be based on various decisions which can be customer specific plugins. 

Google's inclusive language developer documentation discourages usage of this term.

References

External links
Definition from the Linux-HA Project
STONITH Deathmatch Explained (and Some Hints for Resource Agent Authors and Systems Engineers)

Cluster computing
Space Jockey. "Space Jockey" is a science fiction short story by American writer Robert A. Heinlein. Part of his Future History series, it originally appeared in The Saturday Evening Post, April 26, 1947, and was collected in The Green Hills of Earth (and subsequently The Past Through Tomorrow).

The story is set in the near future. It realistically depicts a day in the life of a rocket pilot who pilots commercial passenger spacecraft on scheduled runs between the Earth and the Moon.  It shows the pilot dealing with problems such as an unruly child of a VIP visiting his control room, recalculating the trajectory when the spoiled brat sends the rocket off course, facing a choice between jettisoning cargo and not having enough fuel to reach the destination, and coping with the demands of superiors.

The story begins with a contentious scene between the pilot and his wife, who is unhappy about his irregular schedule and wants him to take a ground job.  Interspersed between the exciting events on the spacecraft, the pilot writes and rewrites a letter to his wife, in the process trying to decide whether he should abandon the job to which he is so well suited.  The story ends on the Moon, where the pilot is offered a more lucrative position, with the condition that he relocate to Luna City. He calls his wife and is relieved when she agrees.

References

External links
 
 Full text of story at Baen Ebooks

Short stories by Robert A. Heinlein
1947 short stories
Works originally published in The Saturday Evening Post
Thermal optimum. A thermal optimum is either a portion of a specified geological time span in which the average temperature was above that of the average temperature for the entire specified time or the optimum range within which a biological process may take place or the ambient optimal range for a species' niche.

In geology, scientists speak of a Holocene thermal optimum or maximum, for example, when referring to the warm period from 7000 to 2500 BC, in which an overall rise in average temperature is seen in evidence from ice cores and from stable isotope data. Scientists are interested in these periods because they may be clues to evolutionary pressures experienced by species during large spans of time.

In biology 
In biology a thermal optimum describes the ideal boundaries for biological processes such as growth and development, and is usually characteristic of a species or population.  Most biological processes are dependent upon enzymatic activity that can be impacted by the organism's body temperature, which in term is a function of the organism's metabolism and environment as each enzyme has a finite window in which it can function properly.  An organism's niche in the environment may then be dependent upon the thermal optima for all of its necessary biological processes.

In animals that inhabit the wave-tossed tidal pools of rocky shores thermal optima vary for each species and dictate the species' tolerance of environmental conditions that lead to increased heating or loss of mechanisms for cooling.  For example, exposure to sunlight when the tide is out, and lack of thermal insulation from the buffering effects of water due to its specific heat capacity may contribute to increased temperature leading to increased desiccation.  An organism that has a high thermal optimum may still be able to function in this environment, while one with a lower thermal optimum may have its metabolic processes shut down during the drying period of exposure.  An organism may be confined to a limited range of habitats due to the population's thermal optima, while another population may have a different range of habitats open to it due to a different thermal optima for its biological processes.  Ultimately the ability to adapt to greater extremes in such a harsh environment as the rocky shores where tide pools are formed may then be discussed in terms of varying environmental thermal optima for different species.  Rising temperatures in the face of stable thermal optima also has implications for parasitic disease transmission and where intervention might become necessary.

References

History of climate variability and change