omniomni/omni-engineering huggingface dataset:
Monomethylhydrazine. Monomethylhydrazine (MMH) is a highly toxic, volatile hydrazine derivative with the chemical formula . It is used as a rocket propellant in bipropellant rocket engines because it is hypergolic with various oxidizers such as nitrogen tetroxide () and nitric acid (). As a propellant, it is described in specification MIL-PRF-27404.

MMH is a hydrazine derivative that was once used in the orbital maneuvering system (OMS) and reaction control system (RCS) engines of NASA's Space Shuttle, which used MMH and MON-3 (a mixture of nitrogen tetroxide with approximately 3% nitric oxide). This chemical is toxic and carcinogenic, but it is easily stored in orbit, providing moderate performance for very low fuel tank system weight. MMH and its chemical relative unsymmetrical dimethylhydrazine (UDMH) have a key advantage that they are stable enough to be used in regeneratively cooled rocket engines. The European Space Agency (ESA) has attempted to seek new options in terms of bipropellant rocket combinations to avoid using deadly chemicals such as MMH and its relatives.

MMH is believed to be the primary active mycotoxin found in mushrooms of the genus Gyromitra, especially the false morel (Gyromitra esculenta). In these cases, MMH is formed by the hydrolysis of gyromitrin.

Monomethylhydrazine is considered to be a possible occupational carcinogen, and the occupational exposure limits to MMH are set at protective levels to account for the possible carcinogenicity.

A known use of MMH is in the synthesis of suritozole.

MMH is also assumed to be the active methylating agent in the drug Temozolomide.

References

Further reading

External links

Rocket fuels
Mycotoxins
Hydrazines
Monoamine oxidase inhibitors
Vitamin B6 antagonists
Organic compounds with 1 carbon atom
Methyl compounds
CDP. CDP may refer to:

Places 
 Census-designated place, an unincorporated area in the U.S. for which census data is collected
 Cuddapah Airport (IATA identifier: CDP), Andhra Pradesh, India

Technology 
 Cache Discovery Protocol, an extension to the BitTorrent file-distribution system
 Certificate in Data Processing, a professional certification conferred by the ICCP
 Charger Downstream Port, a type of battery-charging USB port
 Cisco Discovery Protocol, a proprietary data link network protocol developed by Cisco Systems
 Columbia Data Products, formerly a computer manufacturer, now a software company
 Composers Desktop Project, non-realtime audio digital-signal processing (DSP) software
 Content delivery platform, a system for managing and deploying web content
 Continuous Data Protection, whereby computer data is continuously backed up
 Customer data platform, marketer-based management system for customer profiles

Science and medicine 
 Coronary Drug Project, a trial of treatments for coronary heart disease
 Cytidine diphosphate, a nucleotide

Political parties 
 Constitutional Democratic Party of Japan
 Centrist Democratic Party of the Philippines
 Congress for Democracy and Progress, a political party of Burkina Faso
 Constitutional Democratic Party (disambiguation)
 Christian Democratic Party (Australia)

Other uses 
 Carbon Disclosure Project, of greenhouse gas emissions
 Cassa Depositi e Prestiti, investment bank of Italy
 Center for Domestic Preparedness, a U.S. government emergency response training facility
 Châteauneuf-du-Pape AOC, a French wine appellation
 Coeur de Pirate, a leading Canadian writer and singer of popular music in French and English, real name Béatrice Martin, born Montreal 1989
 Collateralized debt position, a type of structured asset-backed security
 Collett Dickenson Pearce, a British advertising agency

See also
Labyrinth seal. A labyrinth seal is a type of mechanical seal that provides a tortuous path to help prevent leakage. An example of such a seal is sometimes found within an axle's bearing to help prevent the leakage of the oil lubricating the bearing. 

A labyrinth seal may be composed of many grooves that press tightly inside another axle, or inside a hole, so that the fluid has to pass through a long and difficult path to escape. Sometimes screw threads exist on the outer and inner portion. These interlock, to produce the long characteristic path which slows leakage. For labyrinth seals on a rotating shaft, a very small clearance must exist between the tips of the labyrinth threads and the running surface. The "teeth" of the labyrinth seal may be on the rotating shaft (teeth on rotor - TOR) or on the stator (TOS), or both, in an interlocking configuration.

Labyrinth seals on rotating shafts provide non-contact sealing action by controlling the passage of fluid through a variety of chambers by centrifugal motion, as well as by the formation of controlled fluid vortices. At higher speeds, centrifugal motion forces the liquid towards the outside and therefore away from any passages. Similarly, if the labyrinth chambers are correctly designed, any liquid that has escaped the main chamber becomes entrapped in a labyrinth chamber, where it is forced into a vortex-like motion. This acts to prevent its escape, and also acts to repel any other fluid. Because these labyrinth seals are non-contact, they do not wear out.

Many gas turbine engines, having high rotational speeds, use labyrinth seals due to their lack of friction and long life. Because liquid-filled labyrinth seals still generate heat due to the viscosity of the seal oil, and because seal oil can contaminate the process fluids, modern high-performance gas turbines use dry gas seals which use spring-loaded rings with an inert gas in between the faces of the rings to provide the seal. This creates even lower friction and provides a liquid-free seal. However, such engines often have detectable oil leakage into the compression chamber. Indeed, many gas turbine engine seals leak by design.

Labyrinth seals are also found on pistons, which use them to store oil and seal against high pressure during compression and power strokes, as well as on non-rotating shafts. In these applications, it is the long and difficult path and the formation of controlled fluid vortices plus some limited contact-sealing action that creates the seal.

See also
 Tesla valve

References

Seals (mechanical)
Prony equation. The Prony equation (named after Gaspard de Prony) is a historically important equation in hydraulics, used to calculate the head loss due to friction within a given run of pipe.  It is an empirical equation developed by Frenchman Gaspard de Prony in the 19th century:

where hf is the head loss due to friction, calculated from: the ratio of the length to diameter of the pipe L/D, the velocity of the flow V, and two empirical factors a and b to account for friction.

This equation has been supplanted in modern hydraulics by the Darcy–Weisbach equation, which used it as a starting point.

References
. The Prony equation and its replacement by the Darcy–Weisbach equation are on pp. 11–12.

Eponymous equations of physics
Equations of fluid dynamics
Marking blue. Marking blue or layout stain (sometimes called Dykem after trademark erosion of a popular brand, or Prussian blue after the blue pigment) is a dye used in metalworking to aid in marking out rough parts for further machining. It is used to stain or paint a metal object with a very thin layer of dye that can be scratched off using a scriber or other sharp instrument to reveal a bright, yet very narrow line in the metal underneath.

Composition 

Marking blue is made by mixing methylated spirits with shellac and gentian violet.

Alternatives 

A felt tip marker can be used as they are convenient and tend not to dry up as quickly. On rough structures, such as castings or forgings, whitewash or a mixture of chalk and water can be used. A solution of copper sulfate, distilled water, and a few drops of sulfuric acid can be used on machined surfaces.

References 

Dyes
Metalworking measuring instruments
BN. BN, Bn or bn may refer to:

Businesses and organizations

Arts and media
 RTV BN, a Bosnian Serb broadcaster
 Bandai Namco, a gaming and entertainment conglomerate
 Barnes & Noble, an American chain of bookstores
 BN (band), Belarusian rock band

Transport
 Braniff International Airways (IATA code BN), a former American airline in service from 1928 to 1982
 Britten-Norman, a British manufacturer, based on the Isle of Wight, producing Islander and Trislander aircraft
 La Brugeoise et Nivelles, a Belgian railway rolling stock manufacturer, now part of Alstom
 Burlington Northern Railroad, a United States railroad that operated from 1970 to 1996
 Horizon Airlines (Australia) (IATA code BN), a former Australian airline, ending service in 2004

Other businesses and organizations
 Banca Nuova, an Italian bank
 Banque Nationale (disambiguation) several banks
 Barisan Nasional (also known as "National Front"), a political coalition in Malaysia
 British Naturism, the UK naturist society
 Groupe Danone (uronext stock exchange code BN), a French food-products multinational

Military
 Bangladesh Navy
 Battalion, a large unit

Places

Countries
 Brunei (ISO 3166: BN), Southeast Asia
 Bahrain (WMO: BN), West Asia
 Benin (FIPS 10-4: BN), West Africa
 Bosnia and Herzegovina (LOC MARC: BN), Europe

Regions
 BN postcode area, Sussex, England
 Bandarban District, Bangladesh
Province of Benevento, Italy
 Bloomington-Normal, Illinois, US

Place of worship
 Baitun Nur Mosque, Calgary, Alberta, Canada

Science, technology and mathematics
 .bn, Brunei's top-level Internet domain
BN-reactor, a Russian nuclear reactor class
 Batch normalization, in artificial intelligence
 Benzyl functional group (Bn), in organic chemistry
 Billion (disambiguation) (bn), a number
 Boron nitride, a chemical compound
 Bulimia nervosa, an eating disorder
 Dynkin diagram Bn, in mathematical analysis

Other uses
 BN (biscuit), a Franco-British brand of baked food
 Bachelor of Nursing, a professional degree
 Bacon Number, an actor's professional proximity to Kevin Bacon
 Bengali language (ISO 639: bn), spoken in eastern South Asia
 Billion (disambiguation)
CL. CL or cl may refer to:

Arts and entertainment 
 CL (rapper), (born Lee Chae-rin, 1991), singer and rapper, leader of the K-pop girl group 2NE1
 Creative Loafing, a newspaper publisher

Brands and enterprises 
 Colgate-Palmolive's NYSE stock symbol
 Companhia das Lezírias, an agribusiness company in Portugal

Computing and technology 
 , the command-line C/C++ compiler for Microsoft Visual C++
 .cl, Internet country code top-level domain for Chile
 CL register, the low byte of an X86 16-bit CX register
 CAS latency, a measure used in computer memory
 Common Lisp, a programming language
 Common Logic, a framework for a family of logic languages
 Control Language, a scripting language for the IBM AS/400 midrange platform

Industry and technology 
 CL, the prefix for Canadair manufactured aircraft model numbers
 Caseless ammunition

Organizations 
 Catholic League (U.S.), also known as The Catholic League for Religious and Civil Rights
 Communion and Liberation, a lay ecclesial movement within the Catholic Church

Places 
 Chile's ISO country code
 Province of Caltanissetta's ISO 3166-2:IT code
 Călărași County's ISO 3166-2:RO code

Science 
 Cathodoluminescence, emission of photons after excitation by electrons
 Centilitre (cL), a metric measure of volume
 Chlorine, symbol Cl, a chemical element
 cl (elliptic function), cosine lemniscate function
 Clifford algebra, denoted Cl
 Confidence level
 Divisor class group, denoted Cl
 Lift coefficient (CL)
 Topological closure ()

Sports 
 Closer (baseball), a relief pitcher who specializes in finishing a game
 Central League, one of two leagues in Japan's Nippon Professional Baseball
 Continental League, a 1959 proposed third major league for baseball in Canada and the United States

Transportation 
 Acura CL, a Japanese-American mid-size coupe
 Mercedes-Benz CL-Class, a German sports car
 A US Navy hull classification symbol: Light cruiser (CL) 
 Lufthansa CityLine's IATA code

Other uses 
 Certificated Location, a Caravan Club site
 150 (number) or CL in Roman numerals
 Light crude oil's New York Mercantile Exchange symbol
 Shilluk language's ISO 639-1 language code
 Centerline, an engineering drawing symbol, stylized by an overlapping C and L (℄)

See also 
 C1 (disambiguation)
 CI (disambiguation)
 Champions League (disambiguation), various sports organizations
FK. FK or fk may refer to:

Arts and entertainment 
 Flyer Killer, fictional automated robots in the Terminator film franchise
 Fox Kids, a former American children's television programming block
 Funky Kong, a video game character

Place 
 FK postcode area, UK, centred on Falkirk in Scotland.
 Falkland Islands, FIPS PUB 10-4 territory code and ISO 3166 digram
.fk, country code top-level domain (ccTLD) for the Falkland Islands.

Other uses 
 First aid kit
 First Corridor rail coach
 Football Club, abbreviated "FK" in Slavic and Balkan countries
 Foreign key, in database design
 Forward kinematics, in robotics and animation, the use of kinematic equations to find the position of an articulated object
 Fuck, an English-language vulgarity
 Africa West Airlines (IATA airline designator FK)
 Finders Keepers
 kinetic friction, in physics, mechanics
Surgical stainless steel. Surgical stainless steel is a grade of stainless steel used in biomedical applications. The most common "surgical steels" are austenitic SAE 316 stainless and martensitic SAE 440, SAE 420, and 17-4  stainless steels. There is no formal definition on what constitutes a "surgical stainless steel", so product manufacturers and distributors often apply the term to refer to any grade of corrosion resistant steel.

Medical grade stainless
SAE 316 and SAE 316L stainless steel, also referred to as marine grade stainless, is a chromium, nickel, molybdenum alloy of steel that exhibits relatively good strength and corrosion resistance. 316L is the low carbon version of 316 stainless steel.

316L in particular is biocompatible when produced to ASTM F138 / F139. It is a common choice for biomedical implants, as well as body piercings and body modification implants. Immune system reaction to nickel is a potential complication of stainless steel usage within the human body. There are nickel-free nitrogen-strengthened austenitic stainless steel alloys available which address this concern.

316 surgical steel is also used in the manufacture and handling of food and pharmaceutical products where it is often required in order to minimize metallic contamination.

The corrosion resistance properties of all stainless steels is greatly enhanced by the passivation process. ASTM A967 details this process.

Cutlery grade stainless
SAE 440 and SAE 420 stainless steels, known also by the name "Cutlery Stainless Steel", are high carbon steels alloyed with chromium. They have very good corrosion resistance compared to other cutlery steels, but their corrosion resistance is inferior to 316 stainless. Surgical cutting instruments are often made from 440 or 420 stainless due to its high hardness coupled with acceptable corrosion resistance. This type of stainless steel may be slightly magnetic.

General surgical tools are made from other chromium-bearing stainless steels, such as 17-4. ASTM F899 contains a list of commonly used metals for surgical instruments.

See also
Instruments used in general surgery
SAE International
ASTM International

References

Biomaterials
Stainless steel
Surgical instruments
Rich Skrenta. Richard J. Skrenta Jr. (born June 6, 1967) is an American computer programmer and Silicon Valley entrepreneur who created the web search engine blekko.

Early life and education
Skrenta Jr. was born  in Pittsburgh on June 6, 1967. In 1982, at age 15, as a high school student at Mt. Lebanon High School, Skrenta wrote the Elk Cloner virus that infected Apple II computers. It is widely believed to have been one of the first large-scale self-spreading personal computer viruses ever created.

In 1989, Skrenta graduated with a B.A. in computer science from Northwestern University.

Career
Between 1989 and 1991, Skrenta worked at Commodore Business Machines with Amiga Unix.

In 1989, Skrenta started working on a multiplayer simulation game. In 1994, it was launched under the name Olympia as a pay-for-play PBEM game by Shadow Island Games.

Between 1991 and 1995, Skrenta worked at Unix System Labs, and from 1996 to 1998 with IP-level encryption at Sun Microsystems. He later left Sun and became one of the founders of DMOZ. He stayed on board after the Netscape acquisition, and continued to work on the directory as well as Netscape Search, AOL Music, and AOL Shopping.

After his stint at AOL, Skrenta went on to cofound Topix LLC, a Web 2.0 company in the news aggregation and forums market.

In 2005, Skrenta and his fellow cofounders sold a 75% share of Topix to a newspaper consortium made up of Tribune, Gannett, and Knight Ridder.

In the late 2000s, Skrenta headed the startup company Blekko Inc, which was an Internet search engine. Blekko received early investment support from Marc Andreessen and began public beta testing on November 1, 2010.

In 2015, IBM acquired both the Blekko company and search engine for their Watson computer system.

Skrenta was involved in the development of VMS Monster, an old MUD for VMS. VMS Monster was part of the inspiration for TinyMUD. He is also known for his role in developing TASS, an ancestor of tin, the popular threaded Usenet newsreader for Unix systems.

References

External links
Skrenta.com

American computer programmers
MUD developers
1967 births
Living people
Mt. Lebanon High School alumni
Northwestern University alumni
People from Mt. Lebanon, Pennsylvania
DMOZ

sv:Rich Skrenta
Intentional radiator. An intentional radiator is any device that is deliberately designed to produce radio waves.

Radio transmitters of all kinds, including the garage door opener, cordless telephone, cellular phone, wireless video sender, wireless microphone, and many others fall into this category.

In the United States, intentional radiators are regulated under 47 CFR Part 15, Subpart C.

See also
 Spurious emission
 Unintentional radiator (incidental radiator)

Radio electronics
Garage door openers
National Electrical Manufacturers Association. The National Electrical Manufacturers Association (NEMA) is the largest trade association of electrical equipment manufacturers in the United States.  Founded in 1926, it advocates for the industry and publishes standards for electrical products.  Notably, the form of US household electrical outlets and plugs is specified by NEMA.

Description
It was founded in 1926 and maintains its headquarters in Rosslyn, Virginia, in the Washington metropolitan area. Its approximately 350 member companies manufacture products used in the generation, transmission, distribution, control, and end use of electricity. These products are used in utility, industrial, commercial, institutional, and residential applications. The association's Medical Imaging and Technology Alliance (MITA) division represents manufacturers of cutting-edge medical diagnostic imaging equipment including MRI, CT, x-ray, and ultrasound products. Other major end markets include building systems, electrical infrastructure, industrial systems, lighting systems and utility systems. Their combined industries account for 360,000 American jobs in more than 7,000 facilities in every state. Their industry produces $106 billion shipments of electrical equipment and medical imaging technologies per year with $36 billion exports. NEMA also has offices in Mexico City.

In addition to lobbying activities, NEMA has published nearly 1,000 electrical and medical imaging standards, application guides, white papers, and technical papers. Among its major standards are those for electrical enclosures, motors and magnet wire, AC plugs and receptacles; the NEMA connectors are universal in North America and also used by some other countries.

See also
 NEMA connector
 NEMA contact ratings
 NEMA enclosure types
 NEMA stepper motor
 NEMA wattage label

References

External links

 

Electrical safety standards organizations
Electrical trades organizations
Manufacturing in the United States

Organizations based in Arlington County, Virginia
Organizations established in 1926
Trade associations based in the United States
CES. CES may stand for:
Closed ecological system, isolated from the outside
Clean Energy Standards
Constant elasticity of substitution, in economics, a feature of a particular class of production function 
The ISO 639 code for the Czech language
CES, annual technology trade show in Las Vegas produced by the Consumer Technology Association

Technology
Circuit Emulation Service, a telecommunication technology
Cryogenic energy storage
Character encoding scheme, a reversible transformation of sequences of code units to sequences of bytes
Charge-exchange spectroscopy, a diagnostic used in plasma physics

Companies
 ICAO Code designator for China Eastern Airlines

Medicine
Cauda equina syndrome, a serious neurological condition
Cranial electrotherapy stimulation, therapeutic brain stimulation
Camurati-Engelmann disease, also called "Camurati Engelmann syndrome" (CES)
Carboxylesterase, an enzyme that catalyzes the reaction between a carboxylic ester and water

Organization
Caspian Engineers Society
Center for Economic Studies, University of Munich
Center for Ethical Solutions, bioethics think tank in the United States 
Centre for Environmental Studies, former UK research organization
Church Educational System, of The Church of Jesus Christ of Latter-day Saints
Coalition for Economic Survival, a Los Angeles–based community organization
Coalition of Essential Schools, US educational reform
Community Exchange System, international Internet trading network
Commonwealth Employment Service, former Australian Government employment agency
Confédération Européenne de Scoutisme or Confederation of European Scouts
Centre for European Studies (disambiguation), the name of several educational institutions
Center for Election Science, a US-based Approval voting advocacy organization

People
Jean Ces, French boxer of the 1920s

Transportation
Central South station, a proposed MTR station in Hong Kong
Cessnock Airport, IATA airport code "CES"
Cressing railway station, British railway station with station code CES