omniomni/omni-engineering huggingface dataset:
Ninja (Six Flags St. Louis). Ninja is an Arrow Dynamics/Vekoma steel roller coaster located in the Studio Backlot section of Six Flags St. Louis in Eureka, Missouri. It was originally built for and located at Expo 86 in Vancouver, British Columbia, operating as Scream Machine from May to October 1986. It began operating as Ninja at Six Flags St. Louis in 1989. The coaster was started by American manufacturer Arrow Dynamics, but when Arrow fell into bankruptcy during construction, it was sold to Dutch manufacturer Vekoma, who finished it. 

The ride features a loop, a sidewinder and a double corkscrew. The Ninja, like most modern roller coasters, requires a minimum of two employees to dispatch the train. One operates the main panel, which controls the restraints, gates and has a section for the mechanics. The other operator stands at the remote enable. Both operators have to do an all clear sweep and thumbs up, then press their buttons at the same time.

Virtual reality
Six Flags announced on March 3, 2016, that Ninja would receive The New Revolution: Virtual Reality Coaster experience on the ride. Riders have the option to wear Samsung Gear VR headsets, powered by Oculus, to create a 360-degree, 3D experience while riding. The illusion is themed to a fighter jet, where riders fly through a futuristic city as co-pilots battling alien invaders. The feature debuted with the coaster, when it reopened on May 27, 2016. 

In early 2017, Galactic Attack Virtual Reality Coaster was announced to be coming to Ninja, a similar but upgraded version of The New Revolution.

Color
Ninja was originally painted with red track and white supports, and the trains were painted white with red stripes and orange restraints. The colors were modified in 1998, the track was painted black, but the supports remained white and the trains are red with white stripes (though the restraints are still orange).

The ride got a new coat of paint for the 2010 season.

Similarly named rides 
The ride formerly shared a name with Blue Hawk at Six Flags Over Georgia until that coaster's retheming in 2016. Another roller coaster with the same name exists at Six Flags Magic Mountain, but that ride is an Arrow Dynamics suspended swinging coaster.

References

External links
 Ninja at Six Flags St. Louis Official Page

Roller coasters operated by Six Flags
Six Flags St. Louis
Roller coasters in Missouri
Roller coasters introduced in 1989
Yttrium(III) arsenide. Yttrium arsenide is an inorganic compound of yttrium and arsenic with the chemical formula YAs. It can be prepared by reacting yttrium and arsenic at high temperature. Some literature has done research on the eutectic system of it and zinc arsenide.

It reacts with iron, iron(III) arsenide, iron(III) oxide and yttrium(III) fluoride (for doping) at high temperature to obtain superconducting material YFeAsO0.9F0.1 (Tc=10.2 K).

References

External reading

 
 
 

Arsenides
Yttrium compounds
Rock salt crystal structure
Xenon oxytetrafluoride. Xenon oxytetrafluoride () is an inorganic chemical compound. It is an unstable colorless liquid with a melting point of  that can be synthesized by partial hydrolysis of , or the reaction of  with silica or :

 +  →  +  + 

A high-yield synthesis proceeds by the reaction of  with  at .

Like most xenon oxides, it is extremely reactive, and it hydrolyses in water to give hazardous and corrosive products, including hydrogen fluoride:

2 + 4 → 2 + 8 + 3

In addition, some ozone and fluorine is formed.

Reactions
 reacts with  in the following steps:

 +  →  + 2
 +  →  + 2

The  formed is a dangerous explosive, decomposing explosively to Xe and :
2 → 2 + 3

In its liquid form,  exhibits amphoteric behaviour, forming complexes with both strong Lewis bases like  and strong Lewis acids like . It forms a 1:1 adduct with , isostructural with ·, as well as various heavy alkali metal fluorides.

The reaction of  with  provides a convenient synthesis route for .

See also

 Xenon compounds

External links

References

Oxyfluorides
Xenon(VI) compounds
ASCII (squat). The Amsterdam Subversive Center for Information Interchange (ASCII) was a squatted communication laboratory in the Dutch city of Amsterdam. The first incarnation was formed in 1999, based at Herengracht 243a. The lab then moved to the following locations: Jodenbreestraat 24, Kinkerstraat 92–94, Kostverlorenkade 2e, Wibautstraat 7 and Javastraat.

ASCII became legalised when it moved into Jodenbreestraat 24 in January 2000, alongside the radical bookshop Fort van Sjakoo, but started squatting again when faced with a 900% rent increase.

The original aim was to provide a free internet work space for activists and squatters and to promote open source operating systems such as Linux and free software programs such as OpenOffice.org and Mozilla. Members of the collective scavenged and rebuilt computers from trash. In 2005, ASCII was involved with a plan to set up free community wireless internet access across Amsterdam. In 2006, Javastraat was evicted and the group declared a shift towards being a hacklab rather than having a physical space.

See also 
 Hackerspace
 Squatting
 Social centre

References

External links
 Archived ASCII website
 Pictures from the Amsterdam ASCII internet cafe squat, 1999

Infoshops
Evicted squats
Squats in the Netherlands
Hackerspaces
1999 establishments in the Netherlands
2006 disestablishments in the Netherlands
20th-century architecture in the Netherlands
Tungsten(IV) oxide. Tungsten(IV) oxide is the chemical compound with the formula WO2.  The bronze-colored solid crystallizes in a monoclinic cell.  The rutile-like structure features distorted octahedral WO6 centers with alternate short W–W bonds (248 pm). Each tungsten center has the d2 configuration, which gives the material a high electrical conductivity.

WO2 is prepared by reduction of WO3 with tungsten powder over the course of 40 hours at 900 °C. An intermediate in this reaction is the partially reduced, mixed valence species W18O49.
2 WO3  +  W  →  3 WO2

The molybdenum analogue MoO2 is prepared similarly.  Single crystals are obtained by chemical transport technique using iodine. Iodine transports the WO2 in the form of the volatile species WO2I2.

References

Tungsten(IV) compounds
Transition metal oxides
Tungsten ditelluride. Tungsten ditelluride (WTe2) is an inorganic semimetallic chemical compound. In October 2014, tungsten ditelluride was discovered to exhibit an extremely large magnetoresistance: 13 million percent resistance increase in a magnetic field of 60 tesla at 0.5 kelvin.  The resistance is proportional to the square of the magnetic field and shows no saturation. This may be due to the material being the first example of a compensated semimetal, in which the number of mobile holes is the same as the number of electrons. Tungsten ditelluride has layered structure, similar to many other transition metal dichalcogenides, but its layers are so distorted that the honeycomb lattice many of them have in common is in WTe2 hard to recognize. The tungsten atoms instead form zigzag chains, which are thought to behave as one-dimensional conductors. Unlike electrons in other two-dimensional semiconductors, the electrons in WTe2 can easily move between the layers.

When subjected to pressure, the magnetoresistance effect in WTe2 is reduced. Above the pressure of 10.5 GPa magnetoresistance disappears and the material becomes a superconductor.  At 13.0 GPa the transition to superconductivity happens below 6.5 K.

WTe2 was predicted to be a Weyl semimetal and, in particular, to be the first example of a Type II Weyl semimetal, where the Weyl nodes exist at the intersection of the electron and hole pockets.

It has also been reported that terahertz-frequency light pulses can switch the crystal structure of WTe2 between orthorhombic and monoclinic by altering the material's atomic lattice.

Tungsten ditelluride can be exfoliated into thin sheets down to single layers. Monolayer WTe2 was initially predicted to remain a Weyl semimetal in the 1T' crystal phase. It was later shown with transport measurements that, below 50K, a single layer of WTe2 instead acts like an insulator but with an offset current independent of doping by a local electrostatic gate. When using a contact geometry that shorted out conduction along the device edges, this offset current vanished, demonstrating that this nearly quantized conduction was localized to the edge—behavior consistent with monolayer WTe2 being a two-dimensional topological insulator. Identical measurements with two- and three-layer thick samples showed the expected semimetallic response. Subsequent studies using other techniques have been consistent with the transport results, including those using angle-resolved photoemission spectroscopy and microwave-impedance microscopy. Monolayer WTe2 has also been observed to superconduct at moderate doping, with a critical temperature tunable by doping level.

Two- and three-layer thick WTe2 have also been observed to be polar metals, simultaneously hosting metallic behavior and switchable electric polarization. The polarization was theorized to originate from vertical charge transfer between the layers, which is switched by interlayer sliding.

References

Tellurides
Tungsten(IV) compounds
Transition metal dichalcogenides
Monolayers
Tungsten(V) bromide. Tungsten(V) bromide is the inorganic compound with the empirical formula WBr5. The compound consists of bioctahedral structure, with two bridging bromide ligands, so its molecular formula is W2Br10.

Preparation and structure
Tungsten(V) bromide is prepared by treating tungsten powder with bromine in the temperature range 650-1000 °C. The product is often contaminated with tungsten hexabromide.

According to X-ray diffraction, the structure for tungsten pentabromide consists of an edge-shared bioctahedron.

Reactions
Tungsten(V) bromide is the precursor to other tungsten compounds by reduction reactions. For example, tungsten(IV) bromide can be prepared by reduction with aluminium or tungsten. The WBr4 can be purified by chemical vapor transport.
3 WBr5 + Al → 3 WBr4 + AlBr3
Excess tungsten pentabromide and aluminum tribromide are then removed by sublimation at 240 °C.

Tungsten(II) bromide can then be obtained heating the tetrabromide. At 450-500 °C, gaseous pentabromide is evolved leaving yellow-green residue of WBr2. An analogous method can also be applied to the synthesis of tungsten(II) chloride.

Reductive substitution reactions
Because it is relatively easy to reduce tungsten pentahalides, they can be used as alternative synthetic routes to tungsten (IV) halide adducts. For example, reaction of WBr5 with pyridine gives WBr4(py)2.
2 WBr5 + 7 C5H5N → 2 WBr4(C5H5N)2 + bipyridine + C5H5NHBr

References

Bromides
Tungsten halides
Tungsten(V) compounds
Tungsten(V) chloride. Tungsten(V) chloride is an inorganic compound with the formula W2Cl10. This compound is analogous in many ways to the more familiar molybdenum pentachloride.

Synthesis
The material is prepared by reduction of tungsten hexachloride.  One method involves the use of tetrachloroethylene as the reductant
2 WCl6  +  C2Cl4   →   W2Cl10  +  C2Cl6
The blue green solid is volatile under vacuum and slightly soluble in nonpolar solvents.  The compound is oxophilic and is highly reactive toward Lewis bases.

When the same reduction is conducted in the presence of tetraphenylarsonium chloride, one obtains instead the hexachlorotungstate(V) salt:

Structure
The compound exists as a dimer, with a pair of octahedral tungsten(V) centres bridged by two chloride ligands.  The W---W separation is 3.814 Å, which is non-bonding.  The compound is isostructural with Nb2Cl10 and Mo2Cl10.  The compound evaporates to give trigonal bipyramidal WCl5 monomers.

References

Chlorides
Tungsten halides
Tungsten(V) compounds
Tungsten dichloride dioxide. Tungsten dichloride dioxide, or Tungstyl chloride is the chemical compound with the formula . It is a yellow-colored solid. It is used as a precursor to other tungsten compounds. Like other tungsten halides,  is sensitive to moisture, undergoing hydrolysis.

Preparation
 is prepared by ligand redistribution reaction from tungsten trioxide and tungsten hexachloride:

Using a two-zone tube furnace, a vacuum-sealed tube containing these solids is heated to 350 °C. The yellow product sublimes to the cooler end of the reaction tube. No redox occurs in this process. An alternative route highlights the oxophilicity of tungsten:

This reaction, like the preceding one, proceeds via the intermediacy of .

Structure
Gaseous tungsten dichloride dioxide is a monomer. Solid tungsten dichloride dioxide is a polymer consisting of distorted octahedral W centres. The polymer is characterized by two short W-O distances, typical for a multiple W-O bond, and two long W-O distances more typical of a single or dative W-O bond.

Related oxy halides
Tungsten forms a number of oxyhalides including , , . The corresponding bromides (, , ) are also known as is .

Reactions

 is a Lewis acid, forming soluble adducts of the type , where L is a donor ligand such as bipyridine and dimethoxyethane. Such complexes often cannot be prepared by depolymerization of the inorganic solid, but are generated in situ from .

References

Tungsten compounds
Oxychlorides
Tungsten(VI) oxytetrachloride. Tungsten(VI) oxytetrachloride is the inorganic compound with the formula WOCl4.  This diamagnetic solid is used to prepare other complexes of tungsten.  The red crystalline compound is soluble in nonpolar solvents but it reacts with alcohols and water and forms adducts with Lewis bases.

Structure

The solid consists of weakly associated square pyramidal monomers.  The compound is classified as an oxyhalide.

Synthesis and reactions
WOCl4 is prepared from tungsten trioxide:
WO3  +  2 SOCl2   →   WOCl4  +  2 SO2
WCl6 + (Me3Si)2O →   WOCl4 + 2  Me3SiCl
It is "difficult to prepare by other means."

WOCl4 is Lewis acidic.  It is a precursor to catalysts used for polymerization of alkynes.

References

Chlorides
Metal halides
Oxychlorides
Tungsten(VI) compounds
Vanadium nitride. Vanadium nitride, VN, is a chemical compound of vanadium and nitrogen.

Vanadium nitride is formed during the nitriding of steel and increases wear resistance. Another phase, V2N, also referred to as vanadium nitride, can be formed along with VN during nitriding. VN has a cubic, rock-salt structure. There is also a low-temperature form, which contains V4 clusters. 
The low-temperature phase results from a dynamic instability, when the energy of vibrational modes in the high-temperature NaCl-structure phase, are reduced below zero.

It is a strong-coupled superconductor. Nanocrystalline vanadium nitride has been claimed to have potential for use in supercapacitors. The properties of vanadium nitride depend sensitively on the stoichiometry of the material.

References 

Vanadium(III) compounds
Nitrides
Rock salt crystal structure
Chemical lace. Chemical lace (sometimes referred to as Schiffli lace) is a form of machine-made lace. This method of lace-making is done by embroidering a pattern on a sacrificial fabric that has been chemically treated so as to disintegrate after the pattern has been created. Schiffli machines came into use in the late 19th century. Before that, embroidery machines called Swiss hand machine were used to make chemical lace as well as embroideries.

This embroidery is nowadays typically done on a multi-head or multi-needle Schiffli machine or loom that has a very large, continuous and overlapping embroidery field. The lace pattern is designed such that the embroidery thread creates an interlocking series of threads that will, in essence, become a "stand-alone" piece of lace.

After the embroidery is completed the embroidered fabric is immersed in a solution that will not harm the embroidery thread but completely dissolves the sacrificial fabric leaving just the lace.

Utilizing these large machines and this technique, a single piece of lace could be, using today's state-of-the-art machines, over 60 inches wide by 15 yards long.  In practice, this system is used to produce many smaller items with one setup.

Since the original development of chemical lace, other methods have been developed beyond the chemical washing method described above. These include the use of base fabrics that are water-soluble or that disintegrate under heat. These methods are generally too expensive or impractical for large-scale production. These are typically used by smaller embroidery facilities specializing in targeted markets, home-based businesses, or hobbyists.

Chemical lace can be distinguished from needle lace by a slight fuzziness in the threads.

References

External links

 Schiffli Lace and Embroidery Manufacturers Association
 Schiffli Machine Embroidery Guide

Machine-made lace
Embroidery
Annett's key. In British, Australian, French, and Swiss railway signalling, an Annett's key is a form of trapped-key interlocking that locks levers or other items of signalling apparatus, thereby serving as a portable form of interlocking. The purpose is to prevent access from  sidings to the running line without authority. When not in use, the key is normally held in an Annett's lock that is fixed to the lever or concerned apparatus.

History 
The Annett's key takes its name from its inventor, J. E. Annett of the London, Brighton and South Coast Railway. Annett patented his design in 1875; in 1881, that patent was bought out by Saxby and Farmer.

Operation
In British usage, the key may be held in a locked container in the signal box that can only be opened when the corresponding signal lever is turned to danger for traffic on the running line; the lever is locked in position until the key is returned. Alternatively, the key may be attached to the train staff for the section of running line containing the entrance to the siding. At manually-worked level crossings remote from signal boxes, the key to the gates can only be removed for use when the signals for the running line are locked at danger. 

In Australian usage, the key is carried on a specified locomotive.

See also 
 Glossary of rail transport terms

References 

Interlocking systems
Alien Arsenal. Alien Arsenal is a 1999 made-for-television science fiction film directed by David DeCoteau. It is a loose remake of an earlier Charles Band production, Laserblast. It is also known as Teenage Alien Avengers.

Premise
Ralph (Josh Hammond) and Baxter (Danielle Hoover) are two high school nerds who are often tormented by bullies at their school. They find a secret chamber which contains a hoard of hi-tech weapons and armor, their superhero dreams become reality. They use these weapons to get back at the bullies as well as to fulfill some superhero fantasies.

But the alien owners are alerted to the discovery, and return to claim their property in a bid to use it to wipe out humanity. The aliens enlist the help of one of the bullies, Monty (Jerrod Cornish), to get the alien equipment back.

Monty and Ralph discover that they are both being used by the aliens to download an Armageddon Beam which will wipe out all human life on earth.

Production
Director David DeCoteau used the pseudonym Julian Breen. A featurette called the Making of Alien Arsenal was completed in 1999. It is included on some DVDs.

Home Release

The movie has been released on home DVD and is available to stream on various services

Cast
 Josh Hammond as Ralph
 Danielle Hoover as Baxter
 Michele Nordin as Felicia
 Krisztián Kovács as Flash
 Jerrod Cornish as Monty
 William Vogt as Lance
 Riley Smith as Chad
 Dominic Catrambone as Phil
 Stephanie Mennella as Jill
 Chris Olivero as Bill
 Robert Donovan as Mr. Lipkis
 Brenda Blondell as Mrs. O'Houlihan

Reception
TV Guide gave the movie one star calling in an underachieving mixture of Revenge of the Nerds and Laserblast The also found elements of RoboCop and the Mighty Morphin Power Rangers but found the movie lacking in original ideas. Moria gave the movie two out of five stars finding the effects poor and the superheros banal. It did find that the tongue in cheek humor occasionally works.

References

External links
 
 Alien Arsenal review at The Science Fiction, Horror and Fantasy Film Review

1999 films
1990s English-language films
1990s science fiction action films
1990s superhero films
1990s teen films
American action television films
American science fiction action films
American superhero films
Films directed by David DeCoteau
Teen superhero films
1990s American films
1999 science fiction films
English-language science fiction action films
EEI. EEI may refer to:

 Earth's energy imbalance, the difference between energy arriving at and leaving Earth
 Edison Electric Institute, an organisation representing parts of the U.S. electric power industry
 Eindhoven Energy Institute, a department of the Eindhoven University
 Electrical and Electronics Institute of Thailand, a not-for-profit entity under the Foundation for Industrial Development
 Epoch of Extreme Inundations, a hypothetical epoch during which four landforms in the Pontic–Caspian steppe were widely inundated
 Essential elements of information, any critical intelligence information required by intelligence consumers to perform their mission (a term used by US and UK ministries of defence and, until 2014, the US Army)
 Etosha Ecological Institute, an organisation managing research activity in the Etosha National Park in Namibia
Frederic C. Billingsley. Frederic Crockett Billingsley (23 July 1921 – 31 May 2002) was an American engineer, who spent most of his career developing techniques for digital image processing in support of American space probes to the moon, to Mars, and to other planets.

Billingsley published two papers in 1965 using the word pixel, and may have been the first to publish that neologism for picture element.

He was born in New Orleans, Louisiana, and died in Great Falls, Montana.

Image processing contributions

Billingsley was one of the pioneers of digital image processing mentioned in "THE BEST OF NASA'S SPINOFFS," which says:
There also was a need for hardware to record both analog video and digital images on film. No suitable commercial hardware existed, so JPL's Fred Billingsley designed a system called the Video Film Converter (VFC). Built for JPL by Link General Precision, the VFC was used in the 1970s for image playback of the striking pictures returned by the planetary missions of the unmanned Mariner spacecraft.
The JPL document "Overview of VICAR" shows that Billingsley did software as well as hardware:
The VICAR image processing language was defined by JPL employees Stan Bressler, Howard Frieden and Fred Billingsley, and implemented in 1966 at the Jet Propulsion Laboratory to process image data produced by the planetary exploration program.

References

External links
 Pixel History talk dedicated to Fred Billingsley

1921 births
2002 deaths
American electrical engineers
20th-century American engineers
Aichi E11A. The Aichi E11A (九八夜偵, Kyū-hachi Yatei) was an Imperial Japanese Navy flying boat used during the first year of World War II for maritime patrol duties. The Allied reporting name for this type was "Laura"; the Japanese Navy designation was "Type 98 Reconnaissance Seaplane". The Type 98 was quite similar to the earlier E10A Type 96, whose allied name was "Hank". "Lauras" were rare - only 17 were built. It was designed to be launched from cruisers or battleships in order to spot their shellfire at night. The Type 98s were soon diverted to communications and transport duties.

Variants
 E11A1 : Night reconnaissance flying boat for the Imperial Japanese Navy. Production version.

Specifications (Aichi E11A1)

See also

References

Notes

Bibliography

 Francillon, René J. Japanese Aircraft of the Pacific War. London: Putnam & Company Ltd., 1970 (2nd edition 1979). . Pages 489-490.
 Green, William. Warplanes of the Second World War, Volume Five: Flying Boats. London: Macdonald & Co.(Publishers) Ltd., 1962 (5th impression 1972). . Pages 124-125.

External links

E11A
E11A, Aichi
Flying boats
Biplanes
Single-engined pusher aircraft
Aircraft first flown in 1937