omniomni/omni-engineering huggingface dataset:
Double subscript notation. In engineering, double-subscript notation is a notation used to indicate some variable between two points (each point being represented by one of the subscripts). In electronics, the notation is usually used to indicate the direction of current or voltage, while in mechanical engineering it is sometimes used to describe the force or stress between two points, and sometimes even a component that spans between two points (like a beam on a bridge or truss). Although there are many cases where multiple subscripts are used, they are not necessarily called double subscript notation specifically.

Electronic usage 
IEEE standard 255-1963, "Letter Symbols for Semiconductor Devices", defined eleven original quantity symbols expressed as abbreviations.

This is the basis for a convention to standardize the directions of double-subscript labels. The following uses transistors as an example, but shows how the direction is read generally. The convention works like this:

 represents the voltage from C to B. In this case, C would denote the collector end of a transistor, and B would denote the base end of the same transistor. This is the same as saying "the voltage drop from C to B", though this applies the standard definitions of the letters C and B.  This convention is consistent with IEC 60050-121.

 would in turn represent the current from C to E. In this case, C would again denote the collector end of a transistor, and E would denote the emitter end of the transistor. This is the same as saying "the current in the direction going from C to E".

Power supply pins on integrated circuits utilize the same letters for denoting what kind of voltage the pin would receive. For example, a power input labeled VCC would be a positive input that would presumably connect to the collector pin of a BJT transistor in the circuit, and likewise respectively with other subscripted letters. The format used is the same as for notations described above, though without the connotation of VCC meaning the voltage from a collector pin to collector pin; the repetition avoids confusion as such an expression would not exist.

The table above shows only the originally denoted letters; others have found their way into use over time, such as S and D for the Source and Drain of a FET, respectively.

References

Notation
Electronic engineering
Crossbow Technology. Crossbow Technology, Inc. (also referred to as XBOW) was a California-based company that specialized in navigation products, including gyroscopes and guidance, navigation, and control units.

History
Crossbow was founded by Mike A. Horton in 1995. It created products based on technology developed at the University of California, Berkeley, supported by A. Richard Newton and had investment from Cisco, Intel, and the Paladin Capital Group in 2005. Crossbow was one of the first suppliers of the Berkeley-style MICA sensor nodes that it called "motes" which ran the TinyOS operating system.

Crossbow received awards for these products, including a "Best of Sensors Expo Gold 2006" and the BP Helios Award.

Formerly a joint venture, Crossbow Japan became the Sensor Networks and Systems department of Sumitomo Precision Products. On June 5, 2011, Crossbow was acquired by Moog Inc. for about $32 million.

Products 
The AHRS500GA, introduced in 2003, was a completely solid-state FAA-certified attitude and heading reference system (AHRS). It was designed into the Eclipse Aviation mode 500 very light jet and was used in the Capstone Program of the US Federal Aviation Administration.

In 2008, Crossbow released the eKo Pro Series System, a wireless sensor system that monitors crops, vineyards, agriculture, and the environment. In the same year, Crossbow Japan released the NeoMote to monitor energy usage in a building and provide a visual display for energy saving.

References

External links

Defunct electronics companies of the United States
Companies based in San Jose, California
List of industrial archaeology topics. This is a list of topics typically studied by students of industrial archaeology.

It is grouped into industry sectors: Extractive, Manufacturing, Public Utilities, Transport, Miscellaneous.

Extractive

Mining
 Adit
 Air vent
 Mine, Copper mine, Coal mine, Gold mine, Tin mine, Zinc mine
 Shaft mining

Quarrying
 Clayworks
 Sand pits
 Gravel pit
 Powder house

Manufacturing 
 Beam engine
 Brewery
 Brewing
 Brick kiln
 Cement works
 Creamery
 Dairy
 Distillery
 Distilling
 Factory
 Forge
 glass
 Granary
 Hopper
 Kiln
 Pottery
 Silk Industry
 Spinning, Spinning jenny, Spinning mill, Spinning mule
 Stationary engine
 Steam engine
 Warehouse
 Weaving, Loom, Jacquard loom, Dobby loom, Shaft loom, Power loom, Flying shuttle
 Windpump

Mills
 Boring mill
 Cotton mill
 Five-sail windmill
 Flax mill
 Flint mill
 Fulling mill - see Fulling
 Gristmill
 Hand mill
 Iron mill
 Lumber mill
 Millrace
 Mill engine
 Mill stone
 Oil mill
 Post mill
 Rolling mill
 Saw mill
 Smock mill
 Spinning mill
 Steel rolling mill
 Tailrace
 Textile mill
 Tide mill
 Tower mill
 Watermill
 Waterwheel
 Windmill
 Woollen mill

Public Utilities

Electricity
 Power station
 Turbine

Gas
 Gasometer
 Retort house

Water
 Dam
 Pumping station
 Reservoir
 Sewage treatment
 Water treatment
 Water tower

Steam
 District heating

Hydraulic power
 Hydraulic power network

Transport

Aviation

Canals
 Aqueduct
 Canal basin
 Boat lift
 Bridge
 Canal lock
 Culvert
 Flash lock
 Flights of locks
 Inclined plane
 Spillover

Railways
 Air vent
 Ballast pit
 Bridge
 Buffer stops
 Carriage Shed
 Catch point
 Cattle Pens
 Crane
 Crossover
 Culvert
 Cutting
 Embankment
 Footbridge
 Gantry crane (Portainer)
 Goods area
 Goods store
 Ground frame
 Horse tram
 Inclined plane
 Junction (rail)
 Loading bank
 Locomotive shed
 Level crossing
 Milepost
 Platform
 Ropeway
 Signal box (Signal cabin)
 Station
 Station building
 Station house
 Subway
 Track
 Trackbed
 Tram
 Tunnel
 Turnout
 Turntable
 Underpass
 Viaduct
 Waiting room
 Water column
 Water tank
 Water tower

Marine
 Causeway
 Dry dock
 Dock
 Harbour
 Lighthouse
 Pier
 Pump house
 Quay
 Slipway
 Weir

Road
 Bridge
 Unused highway
 Toll road

Miscellaneous 
 Chimney
 Hydraulic pump
 Market house
 Weighbridge

See also
 List of conservation topics
 Conservation in the United Kingdom
 History of science and technology
 Association for Industrial Archaeology
 Society for Industrial Archeology

Archaeology
 
Industrial archaeology
Industrial archaeology
Industry
Atkinson friction factor. Atkinson friction factor is a measure of the resistance to airflow of a duct. It is widely used in the mine ventilation industry but is rarely referred to outside of it.

Atkinson friction factor is represented by the symbol  and has the same units as air density (kilograms per cubic metre in SI units, lbfmin^2/ft^4 in Imperial units).  It is related to the more widespread Fanning friction factor by

in which  is the density of air in the shaft or roadway under consideration and  is Fanning friction factor (dimensionless).  It is related to the Darcy friction factor by 

in which  is the Darcy friction factor (dimensionless).

It was introduced by John J Atkinson in an early mathematical treatment of mine ventilation (1862) and has been known under his name ever since.

See also

 Atkinson resistance

References

 NCB Mining Dept., Ventilation in coal mines: a handbook for colliery ventilation officers,  National Coal Board 1979.

Further reading
 1999 paper giving the derivation of 
 Atkinson, J J, Gases met with in Coal Mines, and the general principles of Ventilation Transactions of the Manchester Geological Society, Vol. III, p.218, 1862

Fluid dynamics
Mine ventilation
Netherworld (video game). Netherworld is a shoot 'em up video game published by Hewson in 1988. It was originally developed by Jukka Tapanimäki for the Commodore 64, and original music was composed by Jori Olkkonen.

Summary
The object is to fly a small spacecraft and collect the required number of diamonds in each level. Once enough diamonds are collected, the craft must reach a teleporter to go to the next level before the time runs out. Aside from the time limit, there are various obstacles, ranging from monsters to items which can damage the craft or block the path. The ship can destroy some obstacles by shooting, sometimes turning them into diamonds as well.

The cover image, that features Tapanimäki's face, was produced from a photograph of the programmer without his knowledge and approval. The original design, depicting a dwarf at the gates of hell, had been shelved following a dispute between Hewson and the original cover artist. Tapanimäki did not see the final version produced by Hewson's local artist, Steve Weston,  until the press conference in London when the game was released.

Cheat codes published in gaming magazines which only worked in an earlier version of the code indicated that a development version of the game had leaked to pirates some six months before the release.

Reception

The Spanish magazine Microhobby awarded the game the following scores: Originality: 80% Graphics: 80% Motion: 80% Sound: 80% Difficulty: 100% Addiction: 100%

References

External links 

 Netherworld , Tec Dubelin Xbox

1988 video games
Amiga games
Amstrad CPC games
Atari ST games
Commodore 64 games
DOS games
Hewson Consultants games
Single-player video games
Video games developed in Finland
ZX Spectrum games
German auxiliary cruiser Pinguin. The Pinguin was a German auxiliary cruiser (Hilfskreuzer) which served as a commerce raider in World War II. The Pinguin was known to the Kriegsmarine as Schiff 33, and designated HSK 5.  The most successful commerce raider of the war, she was known to the British Royal Navy as Raider F. The name Pinguin means penguin in German.

Early history
Formerly a freighter named Kandelfels,  she was built by  AG Weser in 1936, and was owned and operated by the Hansa Line, Bremen. In the winter of 1939/40, she was requisitioned by the Kriegsmarine (KM) and converted to a warship by DeSchiMAG, Bremen. Her main armament was taken from the obsolete battleship .

Raider voyage
Pinguin was one of the first wave of raiders sent out by the Kriegsmarine, sailing on 15 June 1940 under the command of Fregattenkapitän (later Kapitän zur See) Ernst-Felix Krüder.

Slipping through the Denmark Straits, Pinguin made for her patrol area in the Southern Ocean.

In 10½ months at sea she accounted for 28 ships, totalling 136,000 tons (GRT).

Her most successful coup was the capture, on 14 January 1941, of most of the Norwegian whaling fleet in Antarctica, totalling three factory ships and 11 whalers.
These were sent back as prizes to Europe, arriving in Bordeaux, occupied France in March 1941. One of the whalers was retained as an auxiliary raider and re-named Adjutant.

Adjutant went on to lay mines around New Zealand waters.

Fate
On 8 May 1941, Pinguin was sunk in a battle with the British heavy cruiser . She was the first auxiliary cruiser of the Kriegsmarine to be sunk in the war. 532 lives, among them 200 prisoners, were lost when Pinguin blew apart when the mines stored on board took a hit and exploded. Cornwall rescued 60 crew members and 22 prisoners who were originally crew of the 28 merchant ships the raider had either sunk or captured.

Notes

References

Bibliography

 
 
 
 
 
 
 Ivanov, Lyubomir and Ivanova, Nusha. Whaling period. In: The World of Antarctica. Generis Publishing, 2022. pp. 91–94.

External links
 The Royal New Zealand Navy Official History describes the operations of Pinguin

 www.bismarck-class.dk
 DreadnoughtProject.org original plan images of the vessel.
 German Commerce Raider HK33 (Battle LIne series) Part 1 of 3
 German Commerce Raider HK33 (Battle LIne series) Part 2 of 3
 Norwegian Victims of Pinguin
 Marauders of the Sea, German Armed Merchant Ships During W.W. 2
 Cruise Of The Raider HK 33
 Operations of the Pinguin
 Cruises Of The Secret Raiders.

1936 ships
Auxiliary cruisers of the Kriegsmarine
Maritime incidents in May 1941
Ships built in Bremen (state)
World War II commerce raiders
World War II cruisers of Germany
World War II shipwrecks in the Indian Ocean
Naval magazine explosions
ARccOS protection. ARccOS (Advanced Regional Copy Control Operating Solution) is a copy-protection system made by Sony that is used on some DVDs. Designed as an additional layer to be used in conjunction with Content Scramble System (CSS), the system deliberately creates corrupted sectors on the DVD, which cause copying software to produce errors (see bad sector). The corrupted sectors are in areas of the disk that most DVD players do not access, but most copying software does.

Despite being promoted as "fully compatible with available DVD players and drives," some DVDs with ARccOS cannot be played on some DVD players:  Sony DVPCX995, Toshiba SD4700, Harman Kardon DVD101, Microsoft Xbox and others.  Sony has announced a future firmware update for their players to fix this incompatibility issue. One revision of the ARccOS scheme used by Sony was incompatible with a higher number of players than average.  Sony has offered to replace those discs for owners having problems; the replacement discs will have a newer version of ARccOS coding on them, which Sony claims is more compatible. Some DVD rental companies have warned users that the Sony DVDs in question may not play on their machines. Many DVD rippers have been designed to overcome ARccOS protection; it is also naturally overcome by using ddrescue, a Linux utility designed to copy images with errors.

See also
 Compact Disc and DVD copy protection
 Content Scramble System

References

Compact Disc and DVD copy protection
Sony products
Queued Telecommunications Access Method. Queued Telecommunications Access Method (QTAM) is an IBM System/360 communications access method incorporating built-in queuing.  QTAM was an alternative to the lower level Basic Telecommunications Access Method (BTAM).

History 
QTAM was announced by IBM in 1965 as part of OS/360 and DOS/360 aimed at inquiry and data collection.  As announced it also supported remote job entry (RJE) applications, called job processing, which was dropped by 1968. Originally QTAM supported the IBM 1030 Data Collection System, IBM 1050 Data Communications System, the IBM 1060 Data Communications System, the IBM 2671 Paper Tape Reader, AT&T 83B2 Selective Calling Stations, Western Union Plan 115A Outstations, and AT&T Teletype Model 33 or 35 Teletypewriters.  By 1968 terminal support had expanded to include the IBM 2260 display complex, and the IBM 2740 communications terminal.

QTAM devices were attached to a System/360 multiplexor channel through an IBM 2701 Data Adapter or IBM 2702 Transmission Control.  By 1968 support for the IBM 2703 Transmission Control Unit had been added.

QTAM was succeeded by TCAM which provided roughly similar facilities, but was not supported under DOS.

Structure 
QTAM consists of a Message Control Program (MCP) and zero or more Message Processing Programs (MPP).  The MCP handles communications with the terminals, identifies input messages and starts MPPs to process them as required.  This is similar in concept to the much later internet service daemon (inetd) in unix and other systems.

The MCP is assembled by the user installation from a set of macros supplied by IBM.  These macros define the lines and terminals comprising the system, the datasets required, and the procedures used to process received and transmitted messages.

The MPPs, incorporating logic to process the various messages, are supplied by the installation, and use standard OS/360 or DOS/360 data management macros OPEN, CLOSE, GET, and PUT.  PL/I includes the TRANSIENT file declaration attribute to allow MPPs to be written in a high-level language.

References

Other sources 

IBM mainframe operating systems
Self-fabric. Self-fabric, in sewing, is a fabric piece or embellishment made from the same fabric as the main fabric, as opposed to contrast fabric.

Self-fabric used for some pattern pieces such as facings and linings to produce clean garment lines and make the fabric piece blend in with the rest of the garment. Fabric-covered buttons and the welts of a bound buttonhole can be created using self-fabric to minimize their visibility.

Self-fabric can also be used to make design details stand out.  For example, a patch pocket on a coat could be made of contrasting fabric, but have an appliqué made of self-fabric on the pocket.  A very common use of self-fabric as an embellishment is to make two garments that are to be worn together out of different fabrics and use self-fabric from one garment as a trim on the other (such as piping).

References

Sewing
Teruggite. Teruggite is a mineral with the chemical formula Ca4MgAs2B12O22(OH)12·12H2O. It is colorless. Its crystals are monoclinic prismatic. It is transparent. It is not radioactive. It has vitreous luster. Teruggite is rated 2.5 on the Mohs Scale of hardness.

References

Webmineral data
Mindat.org
Handbook of Mineralogy

Calcium minerals
Magnesium minerals
Arsenic minerals
Nesoborates
Monoclinic minerals
Minerals in space group 14
Aubertite. Aubertite is a mineral with the chemical formula CuAl(SO4)2Cl·14H2O. It is colored blue. Its crystals are triclinic pedial. It is transparent. It has vitreous luster. It is not radioactive. Aubertite is rated 2-3 on the Mohs Scale. The sample was collected by J. Aubert (born 1929), assistant director, National Institute of Geophysics, France, in the year 1961. Its type locality is Queténa Mine, Toki Cu deposit, Chuquicamata District, Calama, El Loa Province, Antofagasta Region, Chile.

References
Webmineral.com - Aubertite
Mindat.org - Aubertite
Handbook of Mineralogy - Aubertite

Copper(II) minerals
Aluminium minerals
Sulfate minerals
Chloride minerals
14
Triclinic minerals
Minerals in space group 2
Ægidius Elling. Jens William Ægidius Elling (also Aegidus  or Aegidius) (26 July 1861 – 27 May 1949) was a Norwegian  researcher, inventor and pioneer of gas turbines who is considered to be the father of the gas turbine. He built the first gas turbine that was able to produce more power than needed to run its own components.

Elling was born in and grew up in Oslo, Norway. He studied mechanical engineering at Kristiania Technical College, (now part of Oslo and Akershus University College of Applied Sciences)  graduating in 1881. Between 1885 and 1902, he worked as an engineer and designer at a number of workshops in Sweden and Norway.

His first gas turbine patent was granted in 1884.

In 1903 he completed the first turbine that produced excess power; his original machine used both rotary compressors and turbines to produce  net. He further developed the concept, and by 1912 he had developed a gas turbine system with separate turbine unit and compressor in series, a combination that is now common.  

One major challenge was to find materials that could withstand the high temperatures developed in the turbine to achieve high output powers. His 1903 turbine could withstand inlet temperatures up to 400°Celsius (752°F). Elling understood that if better materials could be found, the gas turbine would be an ideal power source for airplanes. Many years later, Sir Frank Whittle, building on the early work of Elling, managed to build a practical gas turbine engine for an airplane, the jet engine. His gas turbine prototypes from 1903 and 1912 are exhibited at Norsk Teknisk Museum in Oslo.

Elling also did significant development work in other areas, such as steam engine controls, pumps, compressors, vacuum drying et cetera.

In 1914 Elling produced a book called Billig opvarmning: veiledning i at behandle magasinovner økonomisk og letvint.  (), which was published by Aschehoug. Books written by Elling are now rare, and are mostly found in museums and libraries.

References

External links

Norwegian Technical Museum's biography of Elling (Norwegian)

1861 births
1949 deaths
Jet engine pioneers
Norwegian inventors
Ware Shoals Railroad. The Ware Shoals Railroad  was a shortline connecting the town of Ware Shoals, South Carolina, to the Southern Railway and Piedmont and Northern Railway (later Seaboard Coast Line) at Shoals Junction, South Carolina, a distance of .

History

The train carried goods to and from the textile mill located in Ware Shoals, South Carolina, but its main use was the transportation of coal. The railroad was built in 1905 by the Southern Railway, which supplied locomotives to operate the line with during the steam era. By the late 1950s, the railroad dieselized with a single ex-Southern General Electric 44-ton locomotive, numbered 1955.

The railroad ceased operations in 1985 when the textile mill begin to curtail operations. Trackage was pulled up in 1987.

References

Transportation in Abbeville County, South Carolina
Defunct South Carolina railroads
1905 establishments in South Carolina
1985 disestablishments in South Carolina
Liquid Elastomer Molding. The Liquid Elastomer Molding (LEM) gasket consists of a metallic core, coated in selected areas on both sides with a thin layer of silicone with molded-in sealing beads. These beads have differing heights and widths dependent on the clamping load distribution and application requirements. 

The base elastomer coating provides a good overall micro-seal with the silicone beads ensuring optimum sealing in the critical areas. LEM can also include molding on its edge either for sealing of high pressure fluids or for T joints between mating flanges.

References

Seals (mechanical)
Spec RX-7. Spec RX-7 is one of many production-based spec classes, originating in the mid-1990s with the Sports Car Club of America. The class was created by Dave Turner and Mark Holland. The main fault of the class is a lack of nationwide compatibility, with each division having slightly different rulesets from one another. Some allow for vast modification, some allow very little, but they all are based on the premise of equality, with the skill being placed solely on the driver and reducing the need for costly development and "part of the week". Specs range from relatively stock including exhaust and intake, to mildly modified, to Improved Touring  specs. All are based on the 79-85 year model RX-7, with some excluding the 79-80 year models.

Class rules
Since each division has a different set of specs, it is important to locate rules for your area. Below is a small listing of websites to help you locate these rules.

Most divisions (excluding the Improved Touring-based IT7 class) spec suspension, tires, engine modification, and in some cases rollcages and wheels.

References

External links

SpecRX7.com - Washington DC / Mid Atlantic SRX7 website
Texas SRX7 website 
Rocky Mountain SRX7 website
Sports Car Club of America web site
National Auto Sport Association

Racing cars
Sports Car Club of America
Mazda
One-make series