omniomni/omni-engineering huggingface dataset:
DOCSIS Set-top Gateway. DOCSIS Set-top Gateway (or DSG) is a specification describing how out-of-band data is delivered to a cable set-top box. Cable set-top boxes need a reliable source of out of band data for information such as program guides, channel lineups, and updated code images.

Features 
DSG is an extension of the DOCSIS protocol governing cable modems, and applies to all versions of DOCSIS.

The principal features of DSG are:

One-way operation 
The original DOCSIS protocol supports only two way connectivity. A cable modem that is unable to acquire an upstream channel will give up and resume scanning for new channels. Likewise, persistent upstream errors will cause a cable modem to "reinitialize its MAC" and scan for new downstream channels.  This behavior is appropriate for traditional cable modems, but not for cable set-top boxes. A cable set-top box still needs to acquire its out of band data even if the upstream channel is impaired.

The DSG specification introduced one way (downstream only) modes of operation. When upstream errors occur, the set-top enters a downstream-only state, periodically attempting to reacquire the upstream channel.

Defining how to recognize the correct downstream channel  
Set-top out of band data is generally present only on certain downstream channels. The set-top needs a way to distinguish a valid downstream (containing the set-top's data) from an invalid one used only by standalone cable modems.

The DSG specification defines a special downstream keep-alive message so that the set-top can recognize an appropriate downstream channel.

Creating an out-of-band directory 
The Advanced Mode of the DSG Specification introduces a special MAC Management message called the Downstream Channel Descriptor (DCD). The DCD provides a directory identifying the MAC and IP parameters associated with the out of band data streams.

Each data consumer is assigned a special Client Identifier that names the out of band data stream in the DCD.

SNMP MIBs 
The DSG Specification creates two new SNMP management information bases (MIBs) to manage DSG devices. One MIB is used by the set-top, the other by the cable modem termination system (CMTS).

Architecture 
A DSG network comprises three components. The Conditional Access Server generates a stream of out of band data. The DSG Agent (the CMTS) forwards the out of band data and publishes the out of band directory (the DCD). The DSG client on the set-top digests the DSG data.

The set-top device comprises three subcomponents. The DSG-capable cable modem is referred to as the DSG eCM (Embedded Cable Modem). A data consumer is called a DSG Client (there are generally many of these.) Finally, the eCM is configured and controlled by a component called the DSG Client Controller.

See also 
 Residential gateway

References 

Broadcasting standards
Digital cable
Set-top box
A29. A29 or A-29 may refer to:

Aircraft
 A-29 Hudson, a Lockheed World War II aircraft
 Aero A.29, a Czech target tug floatplane of the 1920s
 Focke-Wulf A 29, a variant of the 1927 German Focke-Wulf A 17 airliner with a BMW VI engine
 A-29, another name of the Embraer EMB 314 Super Tucano

Roads
 A29 road (England), a road connecting Capel and Bognor Regis
 A29 autoroute, a road in France connecting Le Havre with the A26 autoroute at Saint-Quentin
 A 29 motorway (Germany), a road connecting Wilhelmshaven and Oldenburg
 Autostrada A29 (Italy), a road connecting Palermo and Mazara del Vallo
 A29 motorway (Netherlands), a road connecting Rotterdam and Steenbergen
 A29 road (Northern Ireland), a road connecting Portrush and Coleraine
 A29 road (Sri Lanka), a road connecting Vavuniya and Horowpathana

Other uses
 HLA-A29, a human serotype
 Spasmolytic A29, a drug
Madelung. Madelung is a German surname. It is also the name of multiple terms in mathematics and science based on people named Madelung.

People
 Erwin Madelung (1881–1972), German physicist
 Georg Hans Madelung (1889–1972), German aeronautical engineer
 Otto Wilhelm Madelung (1846–1926), German surgeon
 Otfried Madelung (1922–2017), Germany solid-state physicist
 Wilferd Madelung (1930–2023), German-American author and scholar of Islamic history

Mathematics and science
 Madelung constant, chemical energy of an ion in a crystal, named after Erwin Madelung
 Madelung equations, Erwin Madelung's equivalent alternative formulation of the Schrödinger equation

Medicine
 Madelung's deformity, characterized by malformed wrists and wrist bones, and short stature, named after Otto Wilhelm Madelung
 Madelung's syndrome, also known as "benign symmetric lipomatosis", named after Otto Wilhelm Madelung

German-language surnames
Reed reaction. The Reed reaction is a chemical reaction that utilizes light to oxidize hydrocarbons to alkylsulfonyl chlorides. This reaction is employed in modifying polyethylene to give  chlorosulfonated polyethylene (CSPE), which is noted for its toughness.

Commercial implementations

Polyethylene is treated with a mixture of chlorine and sulfur dioxide under UV-radiation.  Vinylsulfonic acid can also be prepared beginning with the sulfochlorination of chloroethane. Dehydrohalogenation of the product gives  vinylsulfonyl chloride, which subsequently is hydrolyzed to give vinylsulfonic acid:

=

==

Mechanism
The reaction occurs via a free radical mechanism.  UV-light initiates homolysis of chlorine, producing a pair of chlorine atoms: 

Chain initiation:
Cl2 ->[h\nu] 2Cl. 

Thereafter a chlorine atom attacks the hydrocarbon chain, freeing hydrogen to form hydrogen chloride and an alkyl free radical.  The resulting radical then captures SO2.  The resulting sulfonyl radical attacks another chlorine molecule to produce the desired sulfonyl chloride and a new chlorine atom, which continues the reaction chain.
Chain propagation steps:
{R-H} + .Cl -> {R.} + HCl
{R.} + {:}SO2 -> R-\dot{S}O2
{R-\dot{S}O2} + Cl2 -> {R-SO2-Cl} + Cl.

See also
 Chain reaction

Historical readings
 Reed, C. F. ; ; .

References

Substitution reactions
Carbon-heteroatom bond forming reactions
Name reactions
Johnson bar (vehicle). Johnson bar is the term for several different hand-operated levers used in vehicles. Their distinguishing feature is a positive latch, typically spring-loaded, to hold the lever in a selected position, capable of being operated with one hand.  Some Johnson bars have a fully ratcheting mechanism, some just a series of detents, and others yet simply engaged and disengaged positions.

A common example is the Johnson bar-controlled parking brake found on many trucks and buses. 

Johnson bar is also the North American term for a steam engine's reversing lever, used to control the valve gear. 

The forward/reverse lever on Caterpillar tractors is also called a Johnson bar.

Some light general aviation aircraft (including Piper Cherokees, Beech Musketeers, and some early model Cessnas—such as the Cessna 140)—use Johnson bars to actuate flaps and wheel brakes. The Cessna 162 Skycatcher uses a Johnson bar for flap operation. A small number of older aircraft (including the Mooney M-18, some older M20s and some Progressive Aerodyne SeaReys) also have landing gear actuated by Johnson bars.
The Boeing 707/720 aircraft had a Johnson bar for manually extending the nose landing gear, in case the normal gear extension failed.

See also 

 Cutoff
 Reversing lever

References 

Vehicle design
Vehicle parts
Alacrite. Alacrite (also known as Alloy L-605, Cobalt L-605, Haynes 25, and occasionally F90) is a family of cobalt-based alloys. The alloy exhibits useful mechanical properties and is oxidation- and sulfidation-resistant.

One member of the family, XSH Alacrite, is described as "a non-magnetic, stainless super-alloy whose high surface hardness enables one to achieve a mirror quality polish."  The Institut National de Métrologie in France has also used the material as a kilogram mass standard.

Composition and standardization
L-605 is composed primarily of cobalt (Co), with a specified mixture of chromium (Cr), tungsten (W), nickel (Ni), iron (Fe) and carbon (C), as well as small amounts of manganese (Mn), silicon (Si), and phosphorus (P). The tungsten and nickel improve the alloy's machinability, while chromium contributes to its solid-solution strengthening. The following tolerances must be met to be considered an L-605 alloy:

Properties and Applications 
The alloy was originally developed for application in aircraft, including combustion chambers, liners, afterburners and the hot section of gas turbines. It has also been used in aerospace components and turbine engines as well as drug-eluting and other kinds of stents due to its biocompatibility. When used for implantable medical devices, the ASTM F90-09 and ISO 5832-5:2005 specifications dictate how L-605 is manufactured and tested.

References

Biomaterials
Cobalt alloys
Cadmium fluoride. Cadmium fluoride (CdF2) is a mostly water-insoluble source of cadmium used in oxygen-sensitive applications, such as the production of metallic alloys. In extremely low concentrations (ppm), this and other fluoride compounds are used in limited medical treatment protocols. Fluoride compounds also have significant uses in synthetic organic chemistry. The standard enthalpy has been found to be -167.39 kcal. mole−1 and the Gibbs energy of formation has been found to be -155.4 kcal. mole−1, and the heat of sublimation was determined to be 76 kcal. mole−1.

Preparation
Cadmium fluoride is prepared by the reaction of gaseous fluorine or hydrogen fluoride with cadmium metal or its salts, such as the chloride, oxide, or sulfate.

It may also be obtained by dissolving cadmium carbonate in 40% hydrofluoric acid solution, evaporating the solution and drying in a vacuum at 150 °C.

Another method of preparing it is to mix cadmium chloride and ammonium fluoride solutions, followed by crystallization. The insoluble cadmium fluoride is filtered from solution.

Cadmium fluoride has also been prepared by reacting fluorine with cadmium sulfide. This reaction happens very quickly and forms nearly pure fluoride at much lower temperatures than other reactions used.

Uses

Electronic conductor 

CdF2 can be transformed into an electronic conductor when doped with certain rare earth elements or yttrium and treated with cadmium vapor under high temperature conditions. This process creates blue crystals with varying absorption coefficients depending on the concentrations of the dopant. A proposed mechanism explains that the conductivity of these crystals can be explained by a reaction of Cd atoms with Interstitial F− ions. This creates more CdF2 molecules and releases electrons which are weakly bonded to trivalent dopant ions resulting in n-type conductivity and a hydrogenic donor level.

Safety
Cadmium fluoride, like all cadmium compounds, is toxic and should be used with care.

Cadmium fluoride can cause potential health issues if it is not handled properly. It can cause irritation to the skin and the eyes, so gloves and protective eyewear are advised. The MSDS, or Material Safety Data Sheet, also includes warnings for ingestion and inhalation. Under acidic conditions, at high temperatures, and in moist environments, hydrogen fluoride and cadmium vapors may be released into the air. Inhalation may cause irritation of the respiratory system as well as congestion, fluorosis, and even pulmonary edema in extreme cases. Cadmium fluoride also has the same potential hazards caused by cadmium and fluoride.

References

External links
 National Pollutant Inventory - Cadmium and compounds fact sheet
 National Pollutant Inventory - Fluoride and compounds fact sheet

Fluorides
Metal halides
Cadmium compounds
Fluorite crystal structure
Copper indium gallium selenide. Copper indium gallium (di)selenide (CIGS) is a I-III-VI2 semiconductor material composed of copper, indium, gallium, and selenium. The material is a solid solution of copper indium selenide (often abbreviated "CIS") and copper gallium selenide. It has a chemical formula of CuIn1−xGaxSe2, where the value of x can vary from 0 (pure copper indium selenide) to 1 (pure copper gallium selenide). CIGS is a tetrahedrally bonded semiconductor, with the chalcopyrite crystal structure, and a bandgap varying continuously with x from about 1.0 eV (for copper indium selenide) to about 1.7 eV (for copper gallium selenide).

Structure

CIGS is a tetrahedrally bonded semiconductor, with the chalcopyrite crystal structure. Upon heating it transforms to the zincblende form and the transition temperature decreases from 1045 °C for x = 0 to 805 °C for x = 1.

Applications 

It is best known as the material for CIGS solar cells a thin-film technology used in the photovoltaic industry. In this role, CIGS has the advantage of being able to be deposited on flexible substrate materials, producing highly flexible, lightweight solar panels. Improvements in efficiency have made CIGS an established technology among alternative cell materials.

See also
Copper indium gallium selenide solar cells
CZTS
List of CIGS companies

References

Semiconductor materials
Copper(I) compounds
Indium compounds
Gallium compounds
Selenides
Renewable energy
Dichalcogenides
Photoexcitation. Photoexcitation is the production of an excited state of a quantum system by photon absorption. The excited state originates from the interaction between a photon and the quantum system. Photons carry energy that is determined by the wavelengths of the light that carries the photons. Objects that emit light with longer wavelengths, emit photons carrying less energy. In contrast to that, light with shorter wavelengths emit photons with more energy. When the photon interacts with a quantum system, it is therefore important to know what wavelength one is dealing with. A shorter wavelength will transfer more energy to the quantum system than longer wavelengths.

On the atomic and molecular scale photoexcitation is the photoelectrochemical process of electron excitation by photon absorption, when the energy of the photon is too low to cause photoionization. The absorption of the photon takes place in accordance with Planck's quantum theory.

Photoexcitation plays a role in photoisomerization and is exploited in different techniques:
Dye-sensitized solar cells makes use of photoexcitation by exploiting it in cheaper inexpensive mass production solar cells. The solar cells rely on a large surface area in order to catch and absorb as many high energy photons as possible. Shorter wavelengths are more efficient for the energy conversion compared to longer wavelengths, since shorter wavelengths carry photons that are more energy rich. Light containing shorter wavelengths therefore cause a longer and less efficient conversion of energy in dye-sensitized solar cells.
Photochemistry
Luminescence
Optically pumped lasers use photoexcitation in a way that the excited atoms in the lasers get an enormous direct-gap gain needed for the lasers. The density that is needed for the population inversion in the compound Ge, a material often used in lasers, must become 1020 cm−3, and this is acquired via photoexcitation. The photoexcitation causes the electrons in atoms to go to an excited state. The moment the amount of atoms in the excited state is higher than the amount in the normal ground state, the population inversion occurs. The inversion, like the one caused with germanium, makes it possible for materials to act as lasers.
Photochromic applications. Photochromism causes a transformation of two forms of a molecule by absorbing a photon. For example, the BIPS molecule(2H-l-benzopyran-2,2-indolines) can convert from trans to cis and back by absorbing a photon. The different forms are associated with different absorption bands. In a cis-form of BIPS, the transient absorption band has a value of 21050 cm−1, in contrast to the band from the trans-form, that has a value of 16950 cm−1. The results were optically visible, where the BIPS in gels turned from a colorless appearance to a brown or pink color after repeatedly being exposed to a high energy UV pump beam. High energy photons cause a transformation in the BIPS molecule making the molecule change its structure.

On the nuclear scale photoexcitation includes the production of nucleon and delta baryon resonances in nuclei.

References

Photochemistry
Physical chemistry
Time-resolved spectroscopy
Quantum heterostructure. A quantum heterostructure is a heterostructure in a substrate (usually a semiconductor material), where size restricts the movements of the charge carriers forcing them into a quantum confinement. This leads to the formation of a set of discrete energy levels at which the carriers can exist. Quantum heterostructures have sharper density of states than structures of more conventional sizes.

Quantum heterostructures are important for fabrication of short-wavelength light-emitting diodes and diode lasers, and for other optoelectronic applications, e.g. high-efficiency photovoltaic cells.

Examples of quantum heterostructures confining the carriers in quasi-two, -one and -zero dimensions are:
 Quantum wells
 Quantum wires
 Quantum dots

References

See also
 http://www.ecse.rpi.edu/~schubert/Light-Emitting-Diodes-dot-org/chap04/chap04.htm
 Kitaev's periodic table

Quantum electronics
Nanomaterials
Semiconductor structures
Air Command and Control System. Air Command and Control System (ACCS) is the NATO project planned to replace the NATO Air Command and Control Systems of the 1990s. At the highest level it comprised the Combined Air Operations Centre (CAOC) from which the air battle is run.  Beneath this level of command is the Air Control Centre (ACC), Recognized Air Picture (RAP) Production Centre (RPC) and Sensor Fusion Post (SFP) combined in one entity called ARS. The ARS is the equivalent to the Control and Reporting Centers (CRCs) operated in the 1990s. The ACCS project comprised both static and deployable elements. Under separate funding, NATO intended to procure deployable sensors for the deployable ACCS component (DAC).

Oversight of the project is provided by the NATO Communications and Information Agency (NCIA) in Brussels, Belgium. Until 2012, this was executed by the NATO ACCS Management Organisation (NACMA) Board of Directors, senior representatives of the Nations engaged in the NATO ACCS project.  The Board is responsible to the Secretary General of NATO for the delivery of the project.  

The NCIA AIRC2 PO&S is responsible for the day-to-day management of the project scientific support from former NC3A (now part of the NCIA), system and software engineering support from Systems Support Center (SSC) (as well part of the NCIA), logistic support from the NATO Support and Procurement Agency (NSPA - former NAMSA) and operational support from SHAPE.

History 
The contract to build the ACCS was based on 1990s specifications and awarded to the Air Command Systems International (ACSI) consortium in November 1999. Since 2000, the ACSI has been a part of ThalesRaytheonSystems (TRS). The contract provided the development and testing of the ACCS system core software is now completed. The hardware and software system has been accepted by NATO. Italy is the first nation using ACCS for limited Military Air Operations since April 2015. Germany, France and Belgium has not yet transited to ACCS, as validation nations, leaving 17 other nations still pending.

Fundamental issues with the system design have delayed the implementation by more than 15 years. 

The Integrated System Support of the ACCS system, if operational, will be provided by the NATO Communications and Information Agency (NCIA) supported by in-house System Support Center (SSC).

See also 
 Index of aviation articles
 List of established military terms

References

External links 
 NACMA Press Statement on the NATO Air Command And Control System
 NATO edges towards ACCS 
 NATO Communication and Information Agency - main website
 NATO Programming Centre - main website
 NATO Maintenance and Supply Agency - main website
 SHAPE - main website
 NSPA - main website

NATO
Military installations of NATO
Military technology
Command and control
Permeameter. The permeameter is an instrument for rapidly measuring the electromagnetic permeability of samples of iron or steel with sufficient accuracy for many commercial purposes. The name was first applied by Silvanus P. Thompson to an apparatus devised by himself in 1890, which indicates the mechanical force required to detach one end of the sample, arranged as the core of a straight electromagnet, from an iron yoke of special form; when this force is known, the permeability can be easily calculated.

References

Measuring instruments

permeameter.aspx

www.glossary.oilfield.slb.com/en/Terms/p/permeameter.aspx
Major actinide. Major actinides is a term used in the nuclear power industry that refers to the isotopes of plutonium (239 Pu) uranium (235 U, 238 U) and thorium (232 Th) present in nuclear fuel, as opposed to the minor actinides neptunium, americium, curium, berkelium, and californium, including other isotopes of uranium and plutonium and other actinides.

References
Lurex. Lurex is the registered brand name of the Lurex Company, Ltd. for a type of yarn with a metallic appearance. The yarn is made from synthetic film, onto which a metallic aluminium, silver, or gold layer has been vaporized. "Lurex" may also refer to cloth created with the yarn. The word "lurex" is absent in the English language as a common noun: this is the name of the trademark and the company Lurex Company Limited, which launched the production of such yarn based on nylon and polyester—Lurex in the 1970s. The name was based on the English lure—"temptation; attractiveness".

The Lurex Company
Hugo Wolfram, father of mathematician Stephen Wolfram, served as Managing Director of the Lurex Company; he was also author of three novels.

Lurex in media

Lurex has been a popular material for movie and television costumes.  For example, the bodysuit worn by actress Julie Newmar as Catwoman in the Batman TV series of the 1960s is constructed of black Lurex.

It was also seen in the slasher movie franchise Scream as the killer Ghostface costume known as Father Death to conceal the identity during the murder sprees. Originally it was going to be white but was changed over concerns regarding comparisons to the Ku Klux Klan. 

Referenced in Australian group AC/DC's song 'Rocker' - "Lurex socks, blue suede shoes, V8 car, and tattoos"

Its presence for 'sparkle' at the 1920s-themed 50th anniversary party for MOMA in New York City in 1979 was noted in a news story on the gala event.

Larry Lurex was a name sometimes used by Queen lead singer Freddie Mercury with a few records being released under that name.

See also
Metallic fiber
Lamé (fabric)

References

External links
Official Lurex website

Yarn
Synthetic fibers
Technical fabrics