omniomni/omni-engineering huggingface dataset:
Aleph (disambiguation). Aleph is the first letter of many Semitic abjads (alphabets).

Aleph may also refer to:

Science, technology and mathematics
ALEPH experiment (Apparatus for LEP Physics at CERN), detector of the Large Electron-Positron Collider
Aleph kernel, a computer operating system kernel
Aleph number, in mathematics set theory 
Aleph, an advanced system for inductive logic programming
Aleph (Automated Library Expandable Program), software by Ex Libris Group
Aleph, an investigative data platform containing an archive of government records and open databases, maintained by OCCRP 
Aleph (TeX), a TeX engine extension consolidating Unicode features from Omega and directional features from ε-TeX
Aleph (psychedelic), a psychoactive drug

Literature
 Aleph (novel), by Brazilian author Paulo Coelho
 The Aleph and Other Stories, short story collection by Argentine author Jorge Luis Borges
"The Aleph" (short story), title work of the collection
 Aleph, a character in the Warren Ellis comic series Global Frequency
 Aleph, a plot element in the novel Mona Lisa Overdrive by William Gibson
 Aleph (), a shorthand designation for Codex Sinaiticus, a 4th-century manuscript of the Bible

Music
Aleph (band), a 1980s Italo disco band
 Aleph (pianist), stage name of Fady Abi Saad, born 1980)
 Aleph, a 2013 album by Gesaffelstein
 "The Aleph", a song on the album Saints by Destroy the Runner
 "Aleph", a song by Anahí

Organizations
 Aleph Institute, a Jewish humanitarian organization for both prisoners and military personnel
 ALEPH: Alliance for Jewish Renewal
 Aleph Zadik Aleph, international youth-led fraternal organization for Jewish teenagers
 Aleph Melbourne, an LGBT Jewish organization
 Aleph, the current name of the Japanese cult and terrorist group Aum Shinrikyo

People with the surname
 Patrick Aleph (born 1983), American writer and musician

Other
Aleph (film), a silent film by Wallace Berman
Aleph (journal), an academic journal on Jewish history and the history of science
 Aleph One game engine for the Marathon trilogy
 Aleph Sailing Team, a French America's Cup syndicate
 Mount Aleph, a location in the video game Golden Sun
 Aleph, the protagonist of the video game Shin Megami Tensei II
 Aleph, the highest and most threatening ranking for Abnormalities in the Korean video game Lobotomy Corporation

See also
Alef (disambiguation)
Cementation. Cementation may refer to:

Cementation (biology), the process whereby some sessile bivalve mollusks (and some other shelled invertebrates) attach themselves permanently to a hard substrate
Cementation (geology), the process of deposition of dissolved mineral components in the interstices of sediments
Cementation (medical), a small deposit of calcium, similar to a cyst
Cementation (metallurgy), a process in which ions are reduced to zero valence at a solid metallic interface
Cementation process, an obsolete technique for making steel by carburization of iron
Carburization, a process for surface hardening of low-carbon steel
 Cementation Company, a British construction business
Audio codec. An audio codec, or audio decoder is a device or computer program capable of encoding or decoding a digital data stream (a codec) that encodes or decodes audio. In software, an audio codec is a computer program implementing an algorithm that compresses and decompresses digital audio data according to a given audio file or streaming media audio coding format. The objective of the algorithm is to represent the high-fidelity audio signal with a minimum number of bits while retaining quality. This can effectively reduce the storage space and the bandwidth required for transmission of the stored audio file. Most software codecs are implemented as libraries which interface to one or more multimedia players. Most modern audio compression algorithms are based on modified discrete cosine transform (MDCT) coding and linear predictive coding (LPC).

In hardware, audio codec refers to a single device that encodes analog audio as digital signals and decodes digital back into analog.  In other words, it contains both an analog-to-digital converter (ADC) and digital-to-analog converter (DAC) running off the same clock signal. This is used in sound cards that support both audio in and out, for instance. Hardware audio codecs send and receive digital data using buses such as AC-Link, I²S, SPI, I²C, etc. Most commonly the digital data is linear PCM, and this is the only format that most codecs support, but some legacy codecs support other formats such as G.711 for telephony.

See also
 Comparison of audio coding formats
 List of codecs
 List of open-source codecs
 Transcoding
 Video codec

References

 
Data compression
Meld. Meld or MELD may refer to:

Science, technology and engineering
 Molding (process), the process of manufacturing by shaping the material using a rigid frame
 Melting, the phase transition of a substance from a solid to a liquid
 Welding, a fabrication process that joins materials by fusion
 Meld (software), a computer program for viewing the differences between files
 Model for End-Stage Liver Disease, a scoring system
 Meld, a British Rail Class 55 locomotive

Arts and entertainment
 Meld (cards), a set of matching cards in card games
 Vulcan mind meld, in In Star Trek
 "Meld" (Star Trek: Voyager), an episode of the television series Star Trek: Voyager

Other uses
 Meld (horse), a thoroughbred racehorse

See also
 MELD (disambiguation)
 Melding (disambiguation)
 Merge (disambiguation)
Hop (telecommunications). In telecommunications, a hop is a portion of a signal's journey from source to receiver. Examples include:
The excursion of a radio wave from the Earth to the ionosphere and back to the Earth.  The number of hops indicates the number of reflections from the ionosphere.
A similar excursion from an earth station to a communications satellite to another station, counted similarly except that if the return trip is not by satellite, then it is only a half hop.

In computer networks, a hop is the step from one network segment to the next.

References

Telecommunications engineering
Radio frequency propagation
Coordination of Information on the Environment. Coordination of Information on the Environment (CORINE) is a European programme initiated in 1985 by the European Commission, aimed at gathering information relating to the environment on certain priority topics for the European Union (air, water, soil, land cover, coastal erosion, biotopes, etc.). Since 1994, the European Environment Agency (EEA) integrated CORINE in its work programme. EEA is responsible for providing objective, timely and targeted information on Europe's environment.

Bibliography 

CORINE Biotope Manual, publ. 1992 EU, 
CORINE: Examples of  the Use of the Programme 1985–1990, publ. 1991 EU, 
CORINE: Land Cover Technical Guide, publ. 1994 EU, 
Search for CORINE literature by the EEA

External links
European Environment Agency

European Union and the environment
Environmental statistics
Flare Technology. Flare Technology was a computer hardware company based in Cambridge, United Kingdom.  It was founded in 1986 by Martin Brennan, Ben Cheese, and John Mathieson, former engineers at Sinclair Research.

History 
Flare Technology first worked for Amstrad before developing a technology-demonstrator system called Flare One. The Flare One was intended as a home computer or games console with extensive audio and video capabilities. 

Related to the Loki project they had worked on previously at Sinclair Research, which in turn was derived from the ZX Spectrum home computer, Flare One was based around a Zilog Z80B CPU (working as an 8-bit-per-pixel blitter and a video controller) and a custom 16-bit DSP chip (responsible for 8 channel sound and 3D computation), 1 MB or RAM, with a display resolution of 256 x 256 with 256 colors or 512 x 256 with 16 colors, and an expected price of £200 in 1988. 

Flare One was used in some arcade game cabinets including a line of video quiz machines produced by Bellfruit (A Question of Sport, Beeline, Every Second Counts, Inquizitor, Quizvaders  and Treble Top). The Flare One chipset was further developed into the Konix Multisystem Slipstream prototype. 

In 1989 Martin Brennan was contracted by Atari Corp. to complete and implement the chip design of the unreleased Atari Panther.

Martin Brennan and John Mathieson went on to design the Flare II, which was purchased by Atari and became Atari Jaguar.

References

Defunct computer hardware companies
Defunct computer companies of the United Kingdom
Companies based in Cambridge
Computer companies established in 1986
1986 establishments in England
Touchstone (assaying tool). A touchstone is a small tablet of dark stone such as slate or lydite, used for assaying precious metal alloys. It has a finely grained surface on which soft metals leave a visible trace.

History
The touchstone was used during the Harappa period of the Indus Valley civilization ca. 2600–1900 BC for testing the purity of soft metals. It was also used in Ancient Greece.

The touchstone allowed anyone to easily and quickly determine the purity of a metal sample. This, in turn, led to the widespread adoption of gold as a standard of exchange. Although mixing gold with less expensive materials was common in coinage, using a touchstone one could easily determine the quantity of gold in the coin, and thereby calculate its intrinsic worth.

Operation 

Drawing a line with gold on a touchstone will leave a visible trace. Because different alloys of gold have different colors (see gold), the unknown sample can be compared to samples of known purity. This method has been used since ancient times. In modern times, additional tests can be done. The trace will react in different ways to specific concentrations of nitric acid or aqua regia, thereby identifying the quality of the gold: 24 karat gold is not affected but 14 karat gold will show chemical activity.

See also 
 Litmus test
 Spot analysis
 Streak test

References 

 

Materials science
Jewellery
Gold
Lithics
Inventions of the Indus Valley Civilisation
Indian inventions
Oersted. The oersted (,; symbol Oe) is the coherent derived unit of the auxiliary magnetic field H in the centimetre–gram–second system of units (CGS). It is equivalent to 1 dyne per maxwell.

Difference between CGS and SI systems
In the CGS system, the unit of the H-field is the oersted and the unit of the B-field is the gauss. In the SI system, the unit ampere per meter (A/m), which is equivalent to newton per weber, is used for the H-field and the unit of tesla is used for the B-field.

History
The unit was established by the IEC in the 1930s in honour of Danish physicist Hans Christian Ørsted. Ørsted discovered the connection between magnetism and electric current when a magnetic field produced by a current-carrying copper bar deflected a magnetised needle during a lecture demonstration.

Definition

The oersted is defined as a dyne per unit pole. The oersted is  (≈) amperes per meter, in terms of SI units.

The H-field strength inside a long solenoid wound with 79.58 turns per meter of a wire carrying 1 A is approximately 1 oersted. The preceding statement is exactly correct if the solenoid considered is infinite in length with the current evenly distributed over its surface.

The oersted is closely related to the gauss (G), the CGS unit of magnetic flux density. In vacuum, if the magnetizing field strength is 1 Oe, then the magnetic field density is 1 G, whereas in a medium having permeability  (relative to permeability of vacuum), their relation is
 

Because oersteds are used to measure magnetizing field strength, they are also related to the magnetomotive force (mmf) of current in a single-winding wire-loop:

Stored energy

The stored energy in a magnet, called magnet performance or maximum energy product (often abbreviated BHmax), is typically measured in units of megagauss-oersteds (MG⋅Oe).

See also
 Centimetre–gram–second system of units
 Ampere's model of magnetization

References

Centimetre–gram–second system of units
Units of magnetic induction
Ammonium perchlorate. Ammonium perchlorate ("AP") is an inorganic compound with the formula .  It is a colorless or white solid that is soluble in water. It is a powerful oxidizer. Combined with a fuel, it can be used as a rocket propellant called ammonium perchlorate composite propellant. Its instability has involved it in a number of accidents, such as the PEPCON disaster.

Production
Ammonium perchlorate (AP) is produced by reaction between ammonia and perchloric acid.  This process is the main outlet for the industrial production of perchloric acid.  The salt also can be produced by salt metathesis reaction of ammonium salts with sodium perchlorate.  This process exploits the relatively low solubility of NH4ClO4, which is about 10% of that for sodium perchlorate.

AP crystallises as colorless rhombohedra.

Decomposition
Like most ammonium salts, ammonium perchlorate decomposes before melting. Mild heating results in production of hydrogen chloride, nitrogen, oxygen, and water.

 4 NH4ClO4 → 4 HCl + 2 N2 + 5 O2 + 6 H2O

The combustion of AP is quite complex and is widely studied. AP crystals decompose before melting, even though a thin liquid layer has been observed on crystal surfaces during high-pressure combustion processes. Strong heating may lead to explosions. Complete reactions leave no residue. Pure crystals cannot sustain a flame below the pressure of 2 MPa.

AP is a Class 4 oxidizer (can undergo an explosive reaction) for particle sizes over 15 micrometres and is classified as an explosive for particle sizes less than 15 micrometres.

Applications
During World War I England and France used mixtures featuring ammonium perchlorate (such as "balstine") as a substitute high explosive.

The primary use of ammonium perchlorate is in making solid rocket propellants. When AP is mixed with a fuel (like a powdered aluminium and/or with an elastomeric binder), it can generate self-sustained combustion at pressures far below atmospheric pressure. It is an important oxidizer with a decades-long history of use in solid rocket propellants – space launch (including the Space Shuttle Solid Rocket Booster), military, amateur, and hobby high-power rockets, as well as in some fireworks.

Some "breakable" epoxy adhesives contain suspensions of AP.  Upon heating to 300°C, the AP degrades the organic adhesive, breaking the cemented joint.

Toxicity
Perchlorate itself confers little acute toxicity.  For example, sodium perchlorate has an  of 2–4g/kg and is eliminated rapidly after ingestion. However, chronic exposure to perchlorates, even in low concentrations, has been shown to cause various thyroid problems, as it is taken up in place of iodine.

References

Further reading 

Ammonium compounds
Perchlorates
Pyrotechnic oxidizers
Rocket oxidizers
Oxidizing agents
Explosive chemicals
Mercury(II) fulminate. Mercury(II) fulminate, or Hg(CNO)2, is a primary explosive. It is highly sensitive to friction, heat and shock and is mainly used as a trigger for other explosives in percussion caps and detonators. Mercury(II) cyanate, though its chemical formula is identical, has a different atomic arrangement, making the cyanate and fulminate anionic isomers.

First used as a priming composition in small copper caps beginning in the 1820s, mercury fulminate quickly replaced flints as a means to ignite black powder charges in muzzle-loading firearms. Later, during the late 19th century and most of the 20th century, mercury fulminate  became widely used in primers for self-contained rifle and pistol ammunition; it was the only practical detonator for firing projectiles until the early 20th century. Mercury fulminate has the distinct advantage over potassium chlorate of being non-corrosive, but it is known to weaken with time, by decomposing into its constituent elements. The reduced mercury which results forms amalgams with cartridge brass, weakening it, as well.  Today, mercury fulminate has been replaced in primers by more efficient chemical substances. These are non-corrosive, less toxic, and more stable over time; they include lead azide, lead styphnate, and tetrazene derivatives. In addition, none of these compounds requires mercury for manufacture, supplies of which can be unreliable in wartime.

Preparation
Mercury(II) fulminate is prepared by dissolving mercury in nitric acid and adding ethanol to the solution. It was first prepared by Edward Charles Howard in 1800. The crystal structure of this compound was determined only in 2007.

Silver fulminate can be prepared in a similar way, but this salt is even more unstable than mercury fulminate; it can explode even under water and is impossible to accumulate in large amounts because it detonates under its own weight.

Decomposition
The thermal decomposition of mercury(II) fulminate can begin at temperatures as low as 100 °C, though it proceeds at a much higher rate with increasing temperature.

A possible reaction for the decomposition of mercury(II) fulminate yields carbon dioxide gas, nitrogen gas, and a combination of relatively stable mercury salts.
4 Hg(CNO)2 → 2 CO2 +  N2 +  HgO + 3 Hg(OCN)CN
Hg(CNO)2 → 2 CO +  N2 +   Hg  
Hg(CNO)2 → :Hg(OCN)2 (cyanate or / and isocyanate)
2 Hg(CNO)2 → 2 CO2 +  N2 +  Hg + Hg(CN)2 (mercury(II) cyanide)

See also
 Fulminic acid
 Potassium fulminate

References

External links

National Pollutant Inventory - Mercury and compounds Fact Sheet

Mercury(II) compounds
Fulminates
Explosive chemicals
Pleochroic halo. A pleochroic halo, or radiohalo, is a microscopic, spherical shell of discolouration (pleochroism) within minerals such as biotite that occurs in granite and other igneous rocks. The halo is a zone of radiation damage caused by the inclusion of minute radioactive crystals within the host crystal structure. The inclusions are typically zircon, apatite, or titanite which can accommodate uranium or thorium within their crystal structures.  One explanation is that the discolouration is caused by alpha particles emitted by the nuclei; the radius of the concentric shells are proportional to the particles' energy.

Production
Uranium-238 follows a sequence of decay through thorium, radium, radon, polonium, and lead. These are the alpha-emitting isotopes in the sequence. (Because of their continuous energy distribution and greater range, beta particles cannot form distinct rings.)

The final characteristics of a pleochroic halo depends upon the initial isotope, and the size of each ring of a halo is dependent upon the alpha decay energy. A pleochroic halo formed from U-238 has theoretically eight concentric rings, with five actually distinguishable under a lighted microscope, while a halo formed from polonium has only one, two, or three rings depending on which isotope the starting material is. In U-238 haloes, U-234, and Ra-226 rings coincide with the Th-230 to form one ring; Rn-222 and Po-210 rings also coincide to form one ring. These rings are indistinguishable from one another under a petrographic microscope.

References

Further reading

External links
 Geology of Gentry's "Tiny Mystery",  J. Richard Wakefield, Journal of Geological Education, May 1988.
 Polonium Halo FAQs, TalkOrigins Archive

Radioactive gemstones
Radiometric dating
Lead
Polonium
Radon
Radium
Thorium
SISAL. SISAL (Streams and Iteration in a Single Assignment Language) is a general-purpose single assignment functional programming language with strict semantics, implicit parallelism, and efficient array handling.

SISAL outputs a dataflow graph in Intermediary Form 1 (IF1). It was derived from the Value-oriented Algorithmic Language (VAL), designed by Jack Dennis, and adds recursion and finite streams. It has a Pascal-like syntax and was designed to be a common high-level programming language for numerical programs on a variety of multiprocessors.

History 
SISAL was defined in 1983 by James McGraw et al., at the University of Manchester, Lawrence Livermore National Laboratory (LLNL), Colorado State University and Digital Equipment Corporation (DEC). It was revised in 1985, and the first compiled implementation was made in 1986. Its performance is superior to C and rivals Fortran, according to some sources, combined with efficient and automatic parallelization.

SISAL's name came from grepping "sal" for "Single Assignment Language" from the Unix dictionary /usr/dict/words.

Versions exist for the Cray X-MP, Y-MP, 2; Sequent, Encore Alliant, DEC DEC VAX-11/784, dataflow architectures, KSR1, Inmos Transputers, and systolic arrays.

Architecture

The requirements for a fine-grain parallelism language are better met with a dataflow programming language than a system programming language.

SISAL is more than just a dataflow and fine-grain language. It is a set of tools that convert a textual human readable dataflow language into a graph format (named IF1 - Intermediary Form 1). Part of the SISAL project also involved converting this graph format into runnable C code.

SISAL Renaissance Era 
In 2010 SISAL saw a brief resurgence when a group of undergraduates at Worcester Polytechnic Institute investigated implementing a fine-grain parallelism backend for the SISAL language.

In 2018 SISAL was modernized with indent-based syntax, first-class functions, lambdas, closures and lazy semantics within a project SISAL-IS.

References

Notes

Bibliography

 VAL Overview
 Sisal Language Tutorial

External links 
 SISAL Parallel Programming SourceForge.net project page

Concurrent programming languages
Functional languages
F117 (disambiguation). F-117 is the Lockheed F-117 Nighthawk, an American stealth attack aircraft.

F-117 or F117 may also refer to:

 Pratt & Whitney PW2000 (military designation F117), a turbofan jet engine
 , a British Royal Navy Tribal-class frigate
 , a British Royal Navy Maracaibo-class LST Mk.I tank landing ship 
 F-117A Nighthawk Stealth Fighter 2.0, a video game for the IBM PC from MicroProse (1991)
 F-117A Stealth Fighter, a video game for the NES from MicroProse (1992)
 F-117 Night Storm, a video game for the Sega Genesis / Mega Drive from Electronic Arts (1993)

See also
Harrier. Harrier may refer to:

Animals
 Harrier (bird), birds in the genus Circus
 Harrier (dog)

Media
 Harrier Comics, a defunct British publisher
 Space Harrier, a video game series

Military
 Harrier jump jet, an overview of the Harrier family:
 Hawker Siddeley Harrier, 1st generation Harrier
 British Aerospace Sea Harrier, maritime strike/air defence fighter 
 McDonnell Douglas AV-8B Harrier II, 2nd generation Harrier
 British Aerospace Harrier II, 2nd generation Harrier used by the UK
 Hawker Harrier, experimental biplane torpedo bomber aircraft built in the 1920s

Sport
 Cross-country runner, sometimes referred to as harriers
 Faythe Harriers, an Irish hurling team
 Kidderminster Harriers F.C., an English football team
 One of the following athletics clubs:
 Belgrave Harriers
 Birchfield Harriers

 Coventry Godiva Harriers
 Croydon Harriers
 Eryri Harriers; see Peris Horseshoe
 Hash House Harriers
 Herne Hill Harriers
 Holmfirth Harriers
 Ranelagh Harriers
 Sheffield United Harriers
 Swansea Harriers Athletics Club
 Thames Valley Harriers
 Tipton Harriers

Surname 
 Laura Harrier (born 1990), American actress and former model

Vehicles
 Harrier LR9 Spyder, a sports racing car built in 1994
 Tata Harrier, a compact SUV built since 2018
 Toyota Harrier, a mid-size SUV built since 1997