omniomni/omni-engineering huggingface dataset:
Reliable User Datagram Protocol. In computer networking, the Reliable User Datagram Protocol (RUDP) is a transport layer protocol designed at Bell Labs for the Plan 9 operating system. It aims to provide a solution where UDP is too primitive because guaranteed-order packet delivery is desirable, but TCP adds too much complexity/overhead. In order for RUDP to gain higher quality of service, RUDP implements features that are similar to TCP with less overhead.

Implementations
In order to ensure quality, it extends UDP by means of adding the following features:

 Acknowledgment of received packets
 Windowing and flow control
 Retransmission of lost packets
 Over buffering (Faster than real-time streaming)

RUDP is not currently a formal standard, however it was described in an IETF Internet Draft in 1999. It has not been proposed for standardization.

Cisco RUDP
Cisco in its Signalling Link Terminals (either standalone or integrated in another gateway) uses RUDP for backhauling of SS7 MTP3 or ISDN signaling.

 RUDP v0 (no checksums) is used for SS7 MTP3 backhaul.
 RUDP v1 (with checksum) is used for ISDN PRI backhaul.

The versions are mutually incompatible and differ slightly from the IETF draft. The structure of the Cisco Session Manager used on top of RUDP is also different.

Microsoft R-UDP
Microsoft introduced another protocol which it named R-UDP and used it in its MediaRoom product (now owned by Ericsson) for IPTV service delivery over multicast networks.  This is a proprietary protocol and very little is known about its operation.  It is not thought to be based on the above referenced IETF draft.

See also
 Stream Control Transmission Protocol
 Datagram Transport Layer Security

References

External links
 Plan 9 implementation of RUDP
 https://datatracker.ietf.org/doc/html/draft-ietf-sigtran-reliable-udp-00/
 Cisco Signaling Link Terminal

Transport layer protocols
Internet protocols
Cyanuric chloride. Cyanuric chloride is an organic compound with the formula (NCCl)3.  This white solid is the chlorinated derivative of 1,3,5-triazine.  It is the trimer of cyanogen chloride.  Cyanuric chloride is the main precursor to the popular but controversial herbicide atrazine.

Production
Cyanuric chloride is prepared in two steps from hydrogen cyanide via the intermediacy of cyanogen chloride, which is trimerized at elevated temperatures over a carbon catalyst:
HCN  +  Cl2  →  ClCN  +  HCl

In 2005, approximately 200,000 tons were produced.

Industrial uses
It is estimated that 70% of cyanuric chloride is used in the preparation of the triazine-class pesticides, especially atrazine.  Such reactions rely on the easy displacement of the chloride with nucleophiles such as amines:
(ClCN)3  +  2 RNH2  →  (RNHCN)(ClCN)2  +  RNH3+Cl−
Other triazine herbicides, such as simazine, anilazine and cyromazine are made in an analogous way.

Cyanuric chloride is also used as a precursor to dyes and crosslinking agents. The largest class of these dyes are the sulfonated triazine-stilbene optical brighteners (OBA) or fluorescent whitening agents (FWA) commonly found in detergent formulas and white paper. Many reactive dyes also incorporate a triazine ring. They are also manufactured by way of the chloride displacement reaction shown above.

Reactivity
The chloride centers are easily replaced. Amines give melamine derivatives,  for example in the synthesis of dendrimers:

It reacts with hydrosulfide to give thiocyanuric acid ().

Organic synthesis
Cyanuric chloride is employed as a reagent in organic synthesis for the conversion of alcohols into alkyl chlorides, and carboxylic acids into acyl chlorides: 

It is also used as a dehydrating agent, e.g. in the conversion of amides to nitriles, and for the activation of carboxylic acids for reduction to alcohols.  Heating with DMF gives "Gold's reagent" Me2NCH=NCH=NMe2+Cl−, which is a versatile source of aminoalkylations and a precursor to heterocycles.

Cyanuric chloride can also be used as an alternative to oxalyl chloride in the Swern oxidation.

See also
Thiazyl chloride trimer – structural analogue with sulfur atoms in-place of carbon

References

Inorganic chlorine compounds
Triazines
Dehydrating agents
Catalytic cycle. In chemistry, a catalytic cycle is a multistep reaction mechanism that involves a catalyst. The catalytic cycle is the main method for describing the role of catalysts in biochemistry, organometallic chemistry, bioinorganic chemistry, materials science, etc. 

Since catalysts are regenerated, catalytic cycles are usually written as a sequence of chemical reactions in the form of a loop. In such loops, the initial step entails binding of one or more reactants by the catalyst, and the final step is the release of the product and regeneration of the catalyst. Articles on the Monsanto process, the Wacker process, and the Heck reaction show catalytic cycles.

A catalytic cycle is not necessarily a full reaction mechanism. For example, it may be that the intermediates have been detected, but it is not known by which mechanisms the actual elementary reactions occur.

Precatalysts
Precatalysts are not catalysts but are precursors to catalysts.  Precatalysts are converted in the reactor to the actual catalytic species. The identification of catalysts vs precatalysts is an important theme in catalysis research.

The conversion of a precatalyst to a catalyst is often called catalyst activation.  Many metal halides are precatalysts for alkene polymerization, see Kaminsky catalyst and Ziegler-Natta catalysis.  The precatalysts, e.g. titanium trichloride, are activated by organoaluminium compounds, which function as catalyst activators. Metal oxides are often classified as catalysts, but in fact are almost always precatalysts.  Applications include olefin metathesis and hydrogenation.  The metal oxides require some activating reagent, usually a reducing agent, to enter the catalytic cycle. 

Often catalytic cycles show the conversion of a precatalyst to the catalyst.

Sacrificial catalysts
Often a so-called sacrificial catalyst is also part of the reaction system with the purpose of regenerating the true catalyst in each cycle. As the name implies, the sacrificial catalyst is not regenerated and is irreversibly consumed, thereby not a catalyst at all. This sacrificial compound is also known as a stoichiometric catalyst when added in stoichiometric quantities compared to the main reactant. Usually the true catalyst is an expensive and complex molecule and added in quantities as small as possible. The stoichiometric catalyst on the other hand should be cheap and abundant. "Sacrificial catalysts" are more accurately referred to by their actual role in the catalytic cycle, for example as a reductant.

References

Reaction mechanisms
Catalysis
JP-4. JP-4, or JP4 (for "Jet Propellant") was a jet fuel, specified in 1951 by the United States Department of Defense (MIL-DTL-5624). Its NATO code is F-40. It is also known as avtag.

Usage
JP-4 was a 50-50 kerosene-gasoline blend. It had a lower flash point than JP-1, but was preferred because of its greater availability. It was the primary U.S. Air Force jet fuel between 1951 and 1995.

MC-77 is the Swedish military equivalent of JP-4.

Mixture

JP-4 was a mixture of aliphatic and aromatic hydrocarbons. It was a flammable transparent liquid with clear or straw color, and a kerosene-like smell. It evaporated easily and floated on water. Although it had a low flash point (), a lit match dropped into JP-4 would not ignite the mixture. JP-4 froze at , and its maximum burning temperature was .

JP-4 was a non-conductive liquid, prone to build up static electricity when being moved through pipes and tanks. As it is volatile and has a low flash point, the static discharge could cause a fire. Beginning in the mid-1980s an antistatic agent was added to the fuel to lower the charge buildup and decrease the corresponding risk of fires. Flow rates must be controlled, and all the equipment used must be electrically interconnected and well grounded.

Commercial aviation uses a similar mixture under the name Jet-B, though without the additional corrosion inhibitors and icing inhibitors included in JP-4.

Phase-out

The desire for a less flammable, less hazardous fuel led the U.S. Air Force to phase out JP-4 in favor of JP-8; the transition for USAF operations in Great Britain was made in 1979, and the change was completed throughout the USAF by the end of 1995.

See also
 JP-7
 JP-8
 JP-10
 JPTS
 Aviation fuel

Notes

References
 Faroon, Obaid; Mandell, Diane; Navarro, Hernan. Toxicological Profile for Jet Fuels JP-4 and JP-7. Agency for Toxic Substances and Disease Registry, Atlanta, June 1995.

Aviation fuels
1951 introductions
Systems Management Architecture for Server Hardware. The Systems Management Architecture for Server Hardware (SMASH) is a suite of specifications that deliver industry standard protocols to increase productivity of the management of a data center. 

Distributed Management Task Force developed SMASH Standard- which includes the Server Management Command Line Protocol specification - is a suite of specifications that deliver architectural semantics, industry standard protocols and profiles to unify the management of the data center. Through the development of conformance testing programs, the SMASH Forum will extend these capabilities by helping deliver additional compatibility in cross-platform servers.

External links
 DMTF SMASH initiative

DMTF standards
Networking standards
System administration
Out-of-band management
In-Methylcyclophane. In-Methylcyclophanes are organic compounds and members of a larger family of cyclophanes. These compounds are used to study how chemical bonds in molecules adapt to strain. In-methylcyclophanes in particular have a methyl group in proximity to a benzene ring. This is only possible when both methyl group and ring are attached to the same rigid scaffold. In one In-methylcyclophane molecule this is accomplished with a triptycene frame.

This particular compound is synthesed starting from anthracene with a methyl group added to each arene ring (1,8,9-trimethylanthracene). A triptycene compound is formed from a reaction of this anthracene compound with an aryne in a Diels-Alder reaction in isoamyl nitrite. In this synthesis the precursor to the reactive aryne is 2-amino-6-methylbenzoic acid. Next the methyl substituents are functionalized with bromine groups by the photochemical reaction with N-bromosuccinimide or NBS. The final cyclophane is put together by reaction with 1,3,5-tris(mercaptomethyl)benzene with  nucleophilic sulfhydryl groups and electrophilic alkyl bromides in a nucleophilic aliphatic Substitution.  

X-ray crystallography of the tri-sulfone derivative of this cyclophane shows that the methyl group located 289.6 picometers from the center of the benzene ring. The carbon-to-carbon bond linking the methyl group to the triptycene frame is actually shortened and measures 147.5 to 149.5 pm. The similar bond in the triptycene precursor is 154 pm. Proton NMR analysis shows a chemical shift of 2.52 ppm for the methyl protons compared to that of 3.16 to 3.85 in the anthracene compound. The reason for this anomaly is that the methyl protons are in line with the aromatic ring current of the benzene ring and are therefore severely shielded, an effect similar to the nucleus-independent chemical shift method of analyzing aromaticity.

References 

Organic compounds
Cyclophanes
MELCOR. MELCOR is a fully integrated, engineering-level computer code developed by Sandia National Laboratories for the U.S. Nuclear Regulatory Commission to model  the progression of severe accidents in nuclear power plants. A broad spectrum of severe accident phenomena in both boiling and pressurized water reactors is treated in MELCOR in a unified framework. MELCOR applications include estimation of severe accident source terms, and their sensitivities and uncertainties in a variety of applications.

See also
 Nuclear engineering
 Monte Carlo method
 Nuclear reactor
 MCNP

External links
 SNL MELCOR website
 NRC "Obtaining MELCOR" site
 Wikiversity: Nuclear Engineering

Nuclear safety and security
Physics software
The Descent of Anansi. The Descent of Anansi is a 1982 science fiction novel by American writers Steven Barnes and Larry Niven.

Plot summary
A space station manufactory attempts to become commercially independent from its government backers by exporting super-strong nanowire that can only be manufactured in free-fall.

Following an attempt to sabotage their first delivery and hijack the cargo, the intrepid crew realizes they can escape the hijackers. Their shuttle Anansi can become a modern-day version of its namesake, an African spider-god, by descending to Earth on a thread.

The physics of tidal forces are explained, and the possibilities of orbital tethers to accelerate payloads into higher orbits (or indeed de-orbit shuttles without retro-rockets) are woven into a hard science fiction thriller.

Reception
Dave Langford reviewed The Descent of Anansi for White Dwarf #54, and called it "Fast-moving, predictable, inoffensive."

References

External links
 Page at International Speculative Fiction Database

1982 American novels
1982 science fiction novels
Collaborative novels
Novels by Larry Niven
Desktop Management Interface. The Desktop Management Interface (DMI) generates a standard framework for managing and tracking components in a desktop, notebook or server computer, by abstracting these components from the software that manages them. The development of DMI, 2.0 version June 24, 1998, marked the first move by the Distributed Management Task Force (DMTF) into desktop-management standards.
Before the introduction of DMI, no standardized source of information could provide details about components in a personal computer.

Due to the rapid development of DMTF technologies, such as Common Information Model (CIM), the DMTF defined an "End of Life" process for DMI, which ended on March 31, 2005.

From 1999, Microsoft required OEMs and BIOS vendors to support the DMI interface/data-set in order to have Microsoft certification.

DMI and SMBIOS
DMI exposes system data (including the System Management BIOS (SMBIOS) data) to management software, but the two specifications function independently.

DMI is commonly confused with SMBIOS, which was actually called DMIBIOS in its first revisions.

Optional additional services: MIF data and MIF routines
When software queries a memory-resident agent that resides in the background, it responds by sending data in MIFs (Management Information Format) or activating MIF routines. Static data in a MIF would contain items such as model ID, serial number, memory- and port-addresses. A MIF routine could read memory and report its contents.

DMI and SNMP
DMI can co-exist with SNMP and other management protocols. For example, when an SNMP query arrives, DMI can fill out the SNMP MIB with data from its MIF. A single workstation or server can serve as a proxy agent that would contain the SNMP module and service an entire LAN segment of DMI-capable machines.

See also
 dmidecode
 Desktop management
 lspci
 System Management BIOS
 Web-Based Enterprise Management (WBEM)
 WS-Management

References

Further reading

External links
 The DMI home page links to repositories of DMI-related information including specifications, support-tools, and the Product Registry of DMI-certified products.
 Linux man page for dmidecode
 Large collection of decoded DMI tables for various computer models

DMTF standards
Network management
BIOS
Ballistic nylon. Ballistic nylon is a thick, tough, nylon fabric with several uses. Ballistic nylon was developed by the DuPont corporation as a material for flak jackets for World War II airmen. It was called ballistic because, together with other components, it was intended to protect its wearers from flying debris and fragmentation from bullet and artillery-shell impacts.

Description 
The original specification for ballistic nylon was an  (ounce) nylon fabric made from 1050 denier high tenacity nylon yarn in a 2×2 basketweave. Today it may be any nylon fabric made with a "ballistic weave", typically a 2×2 or 2×3 basketweave. It can be woven from nylon yarns of various denier such as 840 denier and 1680 denier.

Origin 
Ballistic nylon was originally developed by Dupont for flak jackets for World War II airmen. Used either with metal or fiberglass (Doron) inserts or as multiple layers of laminated nylon it was intended to protect the airmen from flying debris and fragmentation from bullet and artillery-shell impacts. It has generally been superseded by Kevlar and other fabrics.

Modern uses 

Although ballistic nylon was originally created and used in flak jackets, its durability and cutting resistance have made it useful for non-combat applications. It can be found in backpacks, luggage, belts and straps, motorcycle jackets, watch bands, and knife sheaths. It can also be used for structural purposes, such as on skin-on-frame kayaks.

Ballistic nylon is used in chainsaw protective chaps covering the fronts of the chainsaw operator's legs. Such chaps are usually made with an outer layer of a tough smooth fabric like nylon or other synthetic fiber, with four plies of ballistic nylon inside. When the moving chainsaw chain contacts the chaps and tears the external layer, the inner plies shred. The strength of the ballistic nylon fiber will generally stop the moving chain quickly by causing the drive clutch to slip.  As a result, the operator is relatively or completely uninjured.

As it is difficult to dye, ballistic nylon is usually black or another dark color.

See also
 Cordura
 Ripstop nylon

References

Body armor
Woven fabrics
China Academy of Launch Vehicle Technology. The China Academy of Launch Vehicle Technology (CALT) is a major state-owned civilian and military space launch vehicle manufacturer in China and one of the major launch service providers in the world. CALT is a subsidiary of the larger China Aerospace Science and Technology Corporation (CASC). It was established in 1957 by Dr. Xue-Sen Qian and is headquartered in Fengtai District, Beijing.

Its major contribution to China's civilian and military launch capability has been the manufacture of the Long March family of rockets. CALT has over 33,000 employees. The current Chief Designer is Long Lehao ().

CALT is also planning two spaceplanes. They would both be single-stage to space sub-orbital rocketplanes. One would be a 10-ton 4-passenger plane that would fly to 100 km at Mach 6. The other would be a 100-ton 20-passenger plane that would fly to 130 km at Mach 8. They would be equipped with liquid methane/liquid oxygen rocket engines. The larger spaceplane would also be able to carry a strap-on space rocket, making it function as the first stage of a two-stage to orbit space launch platform. That rocket would launch above the Karman line, and lift 1–2 tons to LEO.

In 2021, following tests by CALT, United States Secretary of the Air Force Frank Kendall III stated that China was developing and testing a fractional orbital bombardment system.

U.S. sanctions 

In August 2020, the United States Department of Defense released the names of “Communist Chinese military companies” operating directly or indirectly in the United States. CALT was included on the list. 

In November 2020, U.S. President Donald Trump issued an executive order prohibiting U.S. companies and individuals owning shares in companies, including CALT, that the U.S. Department of Defense has listed as having links to the People's Liberation Army.

Subsidiaries
 China Energine
 China Rocket, which developed Jielong 1

References

External links

Qian Xuesen
Space program of the People's Republic of China
Rocket engine manufacturers of China
Technology companies established in 1957
Research institutes in China
1957 establishments in China

China Aerospace Science and Technology Corporation
Defence companies of the People's Republic of China
Arc Infrastructure. Arc Infrastructure (previously known as Brookfield Rail and  WestNet Rail) is a transport infrastructure manager and access provider in Western Australia with a long-term lease on the network from the Government of Western Australia. It operates approximately 5,500 km of standard, narrow and dual gauge rail infrastructure in the southern half of the state.

History

In December 2000, the State Government privatised Westrail, with the Australian Railroad Group, a 50/50 joint venture between United States rail operator Genesee & Wyoming and Australian rural services company Wesfarmers, the successful bidder. Included in the sale was a 49-year lease on the below rail infrastructure network. This part of the business was rebranded as WestNet Rail.

On 1 June 2006, Australian Railroad Group was sold with the above rail rolling stock and terminal assets passing to QR National, and the below rail infrastructure business to Babcock & Brown Infrastructure. Initially Babcock & Brown held a 51% shareholding, the remaining 49% being held by minority shareholders with Babcock & Brown having an option to increase its holding. In March 2008 Babcock & Brown increased its shareholding to 76%. It later took full ownership.

In late 2009, Babcock & Brown Infrastructure was renamed Prime Infrastructure and again by December 2010 to Brookfield Infrastructure Partners following Brookfield Asset Management's purchase of the business. In August 2011, WestNet Rail was rebranded as Brookfield Rail.

In 2017, Brookfield Rail relocated its headquarters from Welshpool to Perth Airport. In July 2017, the company was again rebranded as Arc Infrastructure.

Current operations
Arc Infrastructure has a lease until 2049 on  of rail infrastructure throughout the southern half of Western Australia, from Geraldton in the north, to Leonora and Kalgoorlie in the east, and south to Esperance, Albany and Bunbury.

It is responsible for maintaining the network and granting access to operators.

See also
Wheatbelt railway lines of Western Australia

References

External links

 
Companies based in Perth, Western Australia
Railway infrastructure companies of Australia
Australian companies established in 2006
Railway companies established in 2006
Lightweight Imaging Device Interface Language. Lightweight Imaging Device Interface Language (abbr. LIDIL) is a printer interface definition language used in more recent Hewlett-Packard printers.

This language is commonly used on HP Deskjets that do not support the PCL printer language. As the name suggests, the language only supports the definition of raster documents, and is very limited overall. It is a "host-based" protocol which is advertised with LDL in the CMD: (command set) field of the device ID string. Such models do not support printing ASCII text.

External links
Host-based printing (including LIDIL)

Page description languages
Specification languages
Memory-disk synchronization. Memory-disk synchronisation is a process used in computers that immediately writes to disk any data queued for writing in volatile memory.  Data is often held in this way for efficiency's sake, since writing to disk is a much slower process than writing to RAM.  Disk synchronization is needed when the computer is going to be shut down, or occasionally if a particularly important bit of data has just been written.

In Unix-like systems, a disk synchronization may be requested by any user with the sync command.

See also
 mmap, a POSIX-compliant Unix system call that maps files or devices into memory
 msync, a POSIX-compliant Unix system call that forcefully flush memory to disk and synchronize

Computer memory