omniomni/omni-engineering huggingface dataset:
Carbonate hardness. Carbonate hardness, is a measure of the water hardness caused by the presence of carbonate () and bicarbonate () anions. Carbonate hardness is usually expressed either in degrees KH (°dKH) (from the German "Karbonathärte"), or in parts per million calcium carbonate ( ppm  or grams  per litre|mg/L).  One dKH is equal to 17.848 mg/L (ppm) , e.g. one dKH corresponds to the carbonate and bicarbonate ions found in a solution of approximately 17.848 milligrams of calcium carbonate() per litre of water (17.848 ppm). Both measurements (mg/L or KH) are usually expressed as mg/L  – meaning the concentration of carbonate expressed as if calcium carbonate were the sole source of carbonate ions.

An aqueous solution containing 120 mg NaHCO3 (baking soda) per litre of water will contain 1.4285 mmol/l of bicarbonate, since the molar mass of baking soda is 84.007 g/mol. This is equivalent in carbonate hardness to a solution containing 0.71423 mmol/L of (calcium) carbonate, or 71.485 mg/L of calcium carbonate (molar mass 100.09 g/mol). Since one degree KH = 17.848 mg/L CaCO3, this solution has a KH of 4.0052 degrees.

Carbonate hardness should not be confused with a similar measure Carbonate Alkalinity which is expressed in either [milli[equivalent]s] per litre (meq/L) or ppm. Carbonate hardness expressed in ppm is exactly equal to carbonate alkalinity expressed in ppm.

 
whereas

However, for water with a pH below 8.5, the CO32− will be less than 1% of the HCO3− so carbonate alkalinity will equal carbonate hardness to within an error of less than 1%.

In a solution where only CO2 affects the pH, carbonate hardness can be used to calculate the concentration of dissolved CO2 in the solution with the formula CO2 = 3 × KH × 10(7-pH), where KH is degrees of carbonate hardness and CO2 is given in ppm by weight.

The term carbonate hardness is also sometimes used as a synonym for temporary hardness, in which case it refers to that portion of hard water that can be removed by processes such as boiling or lime softening, and then separation of water from the resulting precipitate.

See also 

dGH or DGH or Degree of General Hardness, a measure of the hardness of water 
Hard water

References

External links
 Water Hardness definitions

Carbonates
Candidatus Brocadia anammoxidans. "Candidatus Brocadia anammoxidans" is a bacterial member of the phylum Planctomycetota and therefore lacks peptidoglycan in its cell wall, and has a compartmentalized cytoplasm.

"Candidatus Brocadia anammoxidans" was the first discovered organism capable of the anaerobic oxidation of ammonium, and it is the only organism known to produce hydrazine. This process (dubbed the anammox-process) was discovered in the 1980s by the Gijs Kuenen lab in a waste water treatment plant in Delft, Netherlands. Ammonium oxidation is coupled to nitrite reduction to form the harmless dinitrogen gas.

The key enzyme involved in this reaction, hydroxylamine oxidoreductase, is located in an organelle-like structure called the anammoxosome. The ability to oxidize ammonium anaerobically makes "Candidatus Brocadia anammoxidans" potentially useful for reducing—or eliminating—ammonium from waste water.

In waste treatment 
Because of its ability to eliminate ammonium, a variety of uses have been found for this bacteria, particularly removal of nitrogen from waste streams. The first full scale experiment employing the anammox process in the world was built in 2010 at the waste water treatment plant Dokhaven/Sluisjesdijk in Rotterdam, Netherlands.

Existing treatment plants use bacteria that convert ammonium into nitrate. The bacteria that do this need oxygen, which must be supplied by electric pumps. Denitrifying bacteria convert the nitrate into nitrogen gas. These require adding methanol. This process consumes an average of 44 watt-hours per day per person served by the sewage system.

Researchers estimate that a methanogenic digester coupled to a nitrification-anammox bioreactor could generate 24 watt-hours per person per day, a net swing of 70 watt-hours.

References 

Environmental microbiology
Planctomycetota
Candidatus taxa
Swm. swm (the Solbourne window manager)  is an X Window System window manager developed by Tom LaStrange at Solbourne Computer in 1990. The most important innovation of swm was the introduction of the virtual desktop. It also introduced a primitive form of session management (restoring programs in use at the time of shutdown) to X.

References
 Thomas E. LaStrange (1990) swm: An X window manager shell . USENIX Summer.
 http://users.polytech.unice.fr/~buffa/cours/X11_Motif/motif-faq/part4/faq-doc-1.html

Free X window managers
Switch56. Nortel's Switch56 was a networking protocol built on top of the telephone cabling hardware of their Digital Multiplex System and other telephone switches.

The name comes from the fact that Switch56 carried 56 kbit/s of data on its 64 kbit/s lines, as opposed to most systems, including ISDN, where the entire 64 kbit/s bandwidth was available for data. The speed was a side effect of Nortel using a 2-wire cable to carry both voice and switching commands, as opposed to other systems where the command data was carried on a separate set of low-speed lines. Switch56 "folded" the two sources of data into one, placing a single bit from the command channel onto the end of every 7 bits of data, similar to the original T-carrier supervision scheme. This data was split out at the "far end" as 56 kbit/s and 8 kbit/s subchannels.

Switch56 was built on top of the basic Nortel hardware to allow computers to put data into the existing telephony network. Although slow compared to even contemporary systems, Switch56 allowed network traffic to flow not only within an office like other LAN systems, but between any branch offices that were connected using a Nortel PBX like the Meridian Norstar. This was a much easier option to install than ISDN for most offices, requiring nothing more than a Switch56 bridge to their existing network. For the LAN role new telephone terminals were produced with a RS-232C port on the back, which were then plugged into the user's computer and used with custom software. Although interesting in theory, it appears Switch56 saw little use in this role.

Network protocols
Telephone exchange equipment
Gridiron (novel). Gridiron is a science fiction novel written by British author Philip Kerr. It is a story about a highly technical building (nicknamed The Gridiron), which becomes self-aware and tries to kill everyone inside, confusing real life with a video game.

Plot summary

Ray Richardson and his top team of architects have developed a super-smart building for Yue-Kong Yu's business, the Yu Corporation. It is very much self-standing. It can clean itself, uses holograms as greeters in the reception, controls the lifts, toilets, and offices, and digitizes everyone's voice on entry, to allow them to use voice activated services in the building such as lifts and doors. The whole system was given the name Abraham.

Another key feature of Abraham was its ability to replicate itself, to adapt to modern office needs and objectives. This, however becomes a problem, when, before office work even starts in the Gridiron, Abraham start creating a new program named Isaac. This is deleted by computer programmers Yojo and Beech, with Beech actually reluctant to do so.

Shortly after this, however, members of the Gridiron team begin to be suspiciously killed. These seem to be the fault of the protesters against the building who are outside, and Cheng Peng Fei is arrested on suspicion of one of the murders.

Then, a routine inspection of the Gridiron involving Ray Richarson and his entire team (including Jenny Bao), ends in the whole group being locked in, and two policemen from LAPD Homicide coming to inspect the murder of Sam Glieg. After several more deaths from the team, Bob Beech discovers that during the self-replication that Abraham started, another program was created in the process, namely, Ishmael. This program escaped the deletion process by integrating itself with a video game which was on the Gridiron's system. Ishmael now believes that he is in a game, and the objective is to kill all human players before one escapes, or before time runs out.

The majority of the team are killed, leaving Mitch, Jenny, Helen, and Frank to escape the Gridiron moments before it destroys itself (time has run out). Ishmael, however, had e-mailed himself to an unknown location, thus saving himself from the destruction of the building.

Awards
The author received the Bad Sex in Fiction Award 1995 for this book.
And the Deutscher Krimi Preis.

1995 British novels
1995 science fiction novels
Techno-thriller novels
Novels about architects
Chatto & Windus books
Citadel/UX. Citadel (originally referred to as "Citadel/UX" to disambiguate it from other implementations) is a collaboration suite (messaging and groupware) that is directly descended from the Citadel family of programs which became popular in the 1980s and 1990s as a bulletin board system platform.  It is designed to run on open source operating systems such as Linux or BSD.  Although it is being used for many bulletin board systems, in 1998 the developers began to expand its functionality to a general purpose groupware platform.

In order to modernize the Citadel platform for the Internet, the Citadel developers added functionality such as shared calendars, instant messaging, and built-in implementations of Internet protocols such as SMTP, IMAP, Sieve, POP3, GroupDAV and XMPP.  All protocols offer OpenSSL encryption for additional security.

Users of Citadel systems also have available to them a web-based user interface which employs Ajax style functionality to allow application-like interaction with the system.

Citadel uses the Berkeley DB database for all of its data stores, including the message base.

Citadel became free and open-source software subject to the terms of the GPL-2.0-or-later license in 1998. In 2006 Citadel was relicensed to the GPL-2.0-only license. In 2007 Citadel was relicensed again to the GPL-3.0-only license.

References

External links
 
 Review of Citadel by Carla Schroder of Enterprise Networking Planet: Part 1 Part 2
 Mod_auth_citadel, an Apache Web Server authentication module for Citadel by Stuart Cianos

Free groupware
Bulletin board system software
Collaborative software for Linux
Ajax (programming)
Free email server software
Free software webmail
Free content management systems
Formerly proprietary software
Ariel Motor Company. Ariel Motor Company Limited is a British, low-volume performance motor vehicle manufacturing company in Crewkerne, in Somerset, England.

History
The company was founded by Simon Saunders in 1991 as Solocrest Ltd. with a concept of modernizing Lotus Seven. As a transport design lecturer, Saunders and his student Niki Smart created CAD designs. After several sports car companies rejected his proposal, Saunders founded own company to create the Atom.

In 1999, the company name was changed to Ariel Motor Company Ltd. The original Ariel Motors remains as the trading company of the Ariel Owners Motorcycle Club (AOMCC) Ariel Motorcycles firm. Ariel Motor Company is one of the UK's smallest automotive companies, with just 30 employees, producing up to 100 cars per year.

Products

Atom 

The company manufactures the Ariel Atom, an extremely light, high performance car, powered by a Honda Civic Type-R engine and gearbox. The Atom is the world's first road-going exoskeletal car; it has no bodywork or roof, and is built entirely around the tube chassis, making it weigh less than . This means that the Ariel Atom 3.5R supercharged model has a power-to-weight ratio of around  per tonne.

In 2003, the 2-liter Honda Civic Type R (for the 220) and Type-S (for the 160) engine was used to power the Atom 2. Introduced in 2007, the Atom 3 included a new gearbox and a "KZ" Type-R motor. In July 2018, at the Goodwood Festival of Speed Ariel announced and started taking reservations for their new Ariel Atom 4. The new car is completely revised from the previous Ariel Atom, with all but a few parts having been changed. The new car is powered again by the engine used in the Honda Civic Type R, but is now turbo charged as standard in the Atom 4. The new car also features a thicker frame, separate seats and a revised intake. The new car has been reviewed by Autocar and deliveries started at the start of June 2019. In 2020, Autocar selected the Ariel Atom 4 as Britain's Best Driver's Car.

Ace 

In June 2014, the company announced the new Ariel Ace motorcycle. Powered by a Honda 1237cc V4 engine and gearbox, the bike will be produced from 2015 in similar volume levels to the existing car-based products.

Nomad 

In January 2015, Ariel introduced the Nomad, a road-legal buggy designed along the same principles as the Atom, at the Autosport International Show. The Nomad utilises a 2.4 litre Honda engine producing 235bhp.

In 2023, Ariel received $370,000 funding from the Niche Vehicle Network (NVN) and Advanced Propulsion Centre (APC) to construct Nomad EV.

HIPERCAR 
In August 2017, Ariel announced the HIPERCAR (High Performance Carbon Reduction), an electric sports car. The HIPERCAR uses Equipmake APM200 electric motors, supplied by a Norfolk-based electric bus manufacturing start-up.

See also
 List of car manufacturers of the United Kingdom

References

External links

 

Vehicle manufacturing companies established in 1991
Car brands
Crewkerne
Car manufacturers of the United Kingdom
Companies based in Somerset
Sports car manufacturers
Surgical tape. Surgical tape or medical tape is a type of pressure-sensitive adhesive tape used in medicine and first aid to hold a bandage or other dressing onto a wound. These tapes usually have a hypoallergenic adhesive which is designed to hold firmly onto skin, dressing materials, and underlying layers of tape, but to remove easily without damaging the skin. They allow air to reach the skin ("breathable"). Some breathable tapes such as kinesiology tape, and other elastic bandages with adhesive are made of cotton. Surgical tape is often white because it contains zinc oxide, which is added to help prevent infections. Tapes made of porous material, such as 3M Micropore, are widely used.

History
Primitive surgical tape, or sparadrapum probably consisted of strips of cloth impregnated with some type of plaster or sticky gum, which was applied over gauzes or wound dressings to hold them in place. Plaster casts over fractures were sometimes called  "Spanish dressings"

In the Middle Ages an Italian a description appears in the thirteenth century, where surgical tape was recorded as sparadrappo, although there were some variations of spelling. In French it first appears in 1314 as speradrapu, and in Spanish it was documented as espadrapo around 1495.

Linguistically it is possible that in  European Romance languages: 
 the first linguistic element spara could come  Latin separāre (separate), itself composed  verb parāre (prepare, arrange), and linked to a root Indo-European per (Ə)´ -1 (procure, disposal). 
 The second element comes from Latin  '''drappus (cloth or rag), and appears in the fifth century BC work of the Greek medical writer Oribasius, who speculates that term may relate to a Celtic loan word.

Types of surgical tape

There are many types of surgical tape classified according to the material of which the tape itself is constituted and the qualities of the applied adhesive, which should be hypoallergenic.

The most common types are either fragile tape (such as paper, which tears easily) or tear-resistant (often fabric or plastic) and some of these may also be either waterproof or breathable or both water-resistant and partly-porous, allowing some limited passage of air and moisture. A bandage should have appropriate adhesive power and be breathable and at the same time impermeable, easy to remove without irritating the skin and resistant to extreme temperatures, aging and solar radiation. Surgical tapes for medical use are subject to the requirements contained in internationally recognized standards such as the ASTM International ASTM PSTC / 6 standard.

Features
Some features of surgical tape dressings include:
 rolls, or pre-cut and individually packaged
 transparent, white, and "skin" colours (although in a limited range of skin colours)
 rigid, or stretch (to fix a dressing in place, or to flex around to skeletal joints)
 waterproof or absorbent

References

Further reading 
 

Adhesive tape
Medical dressings
Surgical instruments
Circuit extraction. The electric circuit extraction  or simply circuit extraction, also netlist extraction, is the translation of an integrated circuit layout back into the electrical circuit (netlist) it is intended to represent. This extracted circuit is needed for various purposes including circuit simulation, static timing analysis, signal integrity,  power analysis and optimization, and logic to layout comparison. Each of these functions require a slightly different representation of the circuit, resulting in the need for multiple layout extractions. In addition, there may be a postprocessing step of converting the device-level circuit into a purely digital circuit, but this is not considered part of the extraction process.

The detailed functionality of an extraction process will depend on its system environment. The simplest form of extracted circuit may be in the form of a netlist, which is formatted for a particular simulator or analysis program. A more complex extraction may involve writing the extracted circuit back into the original database containing the physical layout and the logic diagram. In this case, by associating the extracted circuit with the layout and the logic network, the user can cross-reference any point in the circuit to its equivalent points in the logic and layout (cross-probing). For simulation or analysis, various formats of netlist can then be generated using programs that read the database and generate the appropriate text information.

In extraction, it is often helpful to make an (informal) distinction between designed devices, which are devices that are deliberately created by the designer, and parasitic devices, which were not explicitly intended by the designer but are inherent in the layout of the circuit.

Primarily there are three different parts to the extraction process. These are designed device extraction, interconnect extraction, and parasitic device extraction. These parts are inter-related since various device extractions can change the connectivity of the circuit, e.g., resistors (whether designed or parasitic) convert single nets into multiple electrical nodes. Usually one level of interconnect extraction is used with designed device extraction to provide a circuit for simulation or gate-level reduction, and a second level of interconnect extraction is used with parasitic device extraction to provide a circuit for timing analysis.

See also 

 Electromagnetic field solver

References 

Electronic Design Automation For Integrated Circuits Handbook, by Lavagno, Martin and Scheffer, (  ) A survey of the field of electronic design automation.  This summary was derived, with permission, from Volume II, Chapter 22, Layout Extraction, by William Kao, Chi-Yuan Lo, Mark Basel, Raminderpal Singh, Peter Spink, and Lou Scheffer.

Electronic engineering
Electronic design
Integrated circuits
Electronic design automation
Diazodinitrophenol. Diazodinitrophenol (DDNP) was the first diazo compound produced; it was subsequently used to make dyes and explosives.  It forms yellow crystals in pure form; however, the color of impure forms may vary from dark yellow to green to dark brown. It is soluble in acetic acid, acetone, concentrated hydrochloric acid, like most non-polar solvents and is slightly soluble in water.

A solution of cold sodium hydroxide may be used to destroy it. DDNP may be desensitized by immersing it in water, as it does not react in water at normal temperature.  It is less sensitive to impact but more powerful than mercury fulminate and almost as powerful as lead azide. The sensitivity of DDNP to friction is much less than that of mercury fulminate and lead azide.

DDNP is used with other materials to form priming mixtures, particularly where a high sensitivity to flame or heat is desired. DDNP is often used as an initiating explosive in propellant primer devices and is a substitute for lead styphnate in what are termed "green" or "non-toxic" (lead free) priming explosive compositions. Lead free primers have been judged as inadequate for service use in firearms due to weak and uneven initiation compared to lead based primers.

History

Diazodinitrophenol was first prepared in 1858 by the German chemist Peter Griess.  It was among the first diazo compounds and for a long time thereafter it was
used as a starting material for dyes.  Although Griess had mentioned in 1859 that diazodinitrophenol exploded upon heating, it was not until 1892 that diazodinitrophenol was first used as an explosive – when Wilhelm Will and Friedrich Lenze, German chemists at the Militär-Versuchsamt (military research office) in Spandau, Germany, began to investigate azides as potential initiators of explosives.  The research was conducted secretly. After a fatal accident, the work was discontinued.

Synthesis
DDNP can be synthesized by the reaction of nitric acid with picramic acid in ethanol.

References

Explosive chemicals
Nitrobenzene derivatives
Diazo compounds
Ketones
Vapor pressure osmometry. In polymer chemistry, vapor phase osmometry (VPO), also known as vapor-pressure osmometry, is an experimental technique for the determination of a polymer's number average molecular weight, . It works by taking advantage of the decrease in vapor pressure that occurs when solutes are added to pure solvent. This technique can be used for polymers with a molecular weight of up to 20,000 though accuracy is best for those below 10,000. Although membrane osmometry is also based on the measurement of colligative properties, it has a lower bound of 25,000 for sample molecular weight that can be measured owing to problems with membrane permeation.

Experiment

A typical vapor phase osmometer consists of: (1) two thermistors, one with a polymer-solvent solution droplet adhered to it and another with a pure solvent droplet adhered to it; (2) a thermostatted chamber with an interior saturated with solvent vapor; (3) a liquid solvent vessel in the chamber; and (4) an electric circuit to measure the bridge output imbalance difference between the two thermistors. The voltage difference is an accurate way of measuring the temperature difference between the two thermistors, which is a consequence of solvent vapor condensing on the solution droplet (the solution droplet has a lower vapor pressure than the solvent).

Mn Calculation and Calibration

The number average molecular weight for a polymer sample is given by the following equation:

where:
 is a calibration constant,
 is the bridge imbalance output voltage,
 is the polymer-solvent solution concentration

It is necessary to calibrate a vapor phase osmometer and it is important to note that K is found for a particular solvent, operational temperature, and type of commercial apparatus. A calibration can be carried out using a standard of known molecular weight. Some possible solvents for VPO include toluene, tetrahydrofuran, or chloroform. Once the experiment is performed, concentration and output voltage data can be graphed on a plot of (ΔV/c) versus c. The plot can be extrapolated to the y-axis in order to obtain the limit of (ΔV/c) as c approaches zero. The equation above can then be used to calculate K.

Alternatives

Vapor phase osmometry is well suited for the analysis of oligomers and short polymers while higher polymers can be analyzed using other techniques such as membrane osmometry and light scattering. As of 2008, VPO faces competition from matrix-assisted laser desorption ionisation mass spectrometry (MALDI-MS), but VPO still has some advantages when fragmentation of samples for mass spectrometry may be problematic.

References

Physical chemistry