omniomni/omni-engineering huggingface dataset:
(Benzene)chromium tricarbonyl. (Benzene)chromium tricarbonyl is an organometallic compound with the formula .   This yellow crystalline  solid compound is soluble in common nonpolar organic solvents. The molecule adopts a geometry known as “piano stool” because of the planar arrangement of the aryl group and the presence of three CO ligands as "legs" on the chromium-bond axis.

Preparation
(Benzene)tricarbonylchromium was first reported in 1957 by Fischer and Öfele, who prepared the compound by the carbonylation of bis(benzene)chromium. They obtained mainly chromium carbonyl (Cr(CO)) and traces of Cr(CH)(CO). The synthesis was optimized through the reaction of Cr(CO) and Cr(CH).  For commercial purposes, a reaction of Cr(CO) and benzene is used:
Cr(CO)  +  CH   →   Cr(CH)(CO)  +  3 CO

Applications
Complexes of the type (Arene)Cr(CO)3 have been well investigated as reagents in organic synthesis.. The aromatic ring of (benzene)tricarbonylchromium is substantially more electrophilic than benzene itself, allowing it to undergo nucleophilic addition reactions.

It is also more acidic, undergoing lithiation upon treatment with n-butyllithium.  The resulting organolithium compound can then be used as a nucleophile in various reactions, for example, with trimethylsilyl chloride:

(Benzene)tricarbonylchromium is a useful catalyst for the hydrogenation of 1,3-dienes.  The product alkene results from 1,4-addition of hydrogen.  The complex does not hydrogenate isolated double bonds.

References 

Half sandwich compounds
Organochromium compounds
Carbonyl complexes
Point-to-point laser technology. Point-to-point laser technology (PPLT) refers to a technology that enables a user or surveyor to survey or capture a building's geometry in real time or while on site by translating laser range finder data directly into a Computer-aided design (CAD) or building information models (BIM) work station.

Applications 
Most commonly used for as-built and existing conditions documentation or converting the built environment into a digital format.

Benefits 
PPLT has many benefits in creating BIM or (CAD) models. Entering data directly into a CAD- or BIM-enabled work station allows a user or 'surveyor' to capture and confirm a building's geometry on site. This effectively builds a digital model of a building while it is being measured enabling not only speed but accuracy. Additionally, building in real time can eliminate the need for revisits and also minimizes the need for future interpretation and manipulation of measurements and data by a CAD operator.

Associations 
Since PPLT mainly deals with building surveying there are a few associations that are building surveying specific. There is the Association of Professional Building Surveyors (APBS) in the United States and the Royal Institution of Chartered Surveyors (RICS) in Britain. Whereas building surveying is offered at the curriculum level in Europe it still is in its nascent stages in the United States.

Certifications 
Both the APBS and RICS offer certification methods and programs. The APBS has the professional building surveyor (PBS) certifications.

References

Building engineering
Anglo Great Lakes Graphite Plant. The Anglo Great Lakes Graphite Plant was a large graphite works situated in the North East of England. It was positioned at Lemington in Newcastle upon Tyne, on the north bank of the River Tyne. The plant was operated by the Anglo Great Lakes Corporation and produced high grade carbon for use in Magnox nuclear reactors, Advanced Gas-cooled Reactors and low grade carbon for use in carbon arc burning.

History
The plant was built on the Newburn Haugh. During World War I a munitions factory was built on the site. The factory was demolished following World War II and the land reclaimed. The graphite plant was then constructed in 1958 for the conversion of carbon into graphite for use in the nuclear industry, supplying graphite for nuclear power stations including; Bradwell, Dungeness 'A', Hinkley Point 'B', Hunterston 'A', Hunterston 'B', Latina & Oldbury.
The plant continued operating until the early 1990s and was subsequently demolished, along with the neighbouring Stella North power station. The two adjoining sites were redeveloped as an industrial/business park, Newburn Riverside.  The reclamation scheme cost £46 million. One North East, North East Ambulance Trust and DEFRA are amongst the organisations which now have premises there.

References

1958 establishments in England
Buildings and structures in Newcastle upon Tyne
Manufacturing companies of England
HawkSat-1. HawkSat-1 was a single-unit CubeSat which was built and is being operated by the Hawk Institute for Space Sciences (HISS), Pocomoke City, Maryland. It is based on a Pumpkin Inc. CubeSat kit, and carries a technology demonstration payload, primarily as a proof of concept mission, testing command, data and power subsystems, as well as solar panels and communications.

It carries a commercial material exposure research payload for an undisclosed "major aerospace company", which exposes a number of material samples to space, and records the effects of exposure on the materials. The data was to be sent to Earth by means of a storage and dump communication system.

Launch 
It was successfully launched on an Orbital Sciences Corporation Minotaur I launch vehicle from Pad 0B at the Mid-Atlantic Regional Spaceport, at 23:55 UTC on 19 May 2009. It was a tertiary payload, with TacSat-3 as the primary payload and PharmaSat as the secondary. Two other CubeSats, AeroCube-3 and CP6, were launched on the same launch vehicle, and together the three satellites are known as the CubeSat Technology Demonstration mission.

Mission 
The satellite was successfully deployed in orbit, but no signals were received.

Atmospheric entry 
The satellite reentered in the atmosphere of Earth on 4 September 2011.

See also 

 List of CubeSats

References

External links 
 
 http://www.hawkspace.org/history.php Hawk Institute for Space Sciences - history

Spacecraft launched in 2009
CubeSats
Spacecraft launched by Minotaur rockets
Spacecraft which reentered in 2011
Munck Cranes. The company Munck Cranes  (Sverre Munck A/S) was founded on 25 October 1924 by Mr. Sverre Munck. He was educated as an electrical engineer at the University of Trondheim, Norway. The company initially started as a trading company with products ranging from fuses and light bulbs to escalators, elevators and electric wire rope hoists, the latter being of foreign make.

Manufacturing
The first Munck manufacturing plant was completed in 1946, and the number of employees increased rapidly from 30 to 300 people. This was mainly as a result of an order for 18 units of trolley buses for Bergen Sporvei - the local bus company, but also orders from several other bus companies in Norway. During this time, the first Munck electric wire rope hoist was designed, and full production commenced, involving hoists and industrial cranes for all major types of industry on shore as well as on board ships.

Export pioneer 

The Munck Company has been a pioneer within the Norwegian export industry. The very first Munck hoist for export was shipped to Sweden in 1948, and the same year also to England. Thereafter the export to very many overseas markets picked up rapidly.

Later, in the 1950s and 1960s, subsidiary companies were established in the United States, Canada, Great Britain, Sweden, Brazil and Belgium. Further, a network of agents were established in other parts of the world. Still today, Munck is working very closely with many of these companies, although they are managed by local owners.

Ownership 

Munck Cranes AS is part of the Furnes Hamjern Group of Companies. As from October 1996 Munck Cranes AS is wholly owned by Øyhovden Invest AS

References

Manufacturing companies of Norway
Yakovlev VVP-6. The Yakovlev VVP-6 was an experimental design for a flying support and surface-to-air missile platform, capable of vertical takeoff and landing. It never progressed beyond the model stage.

Development
Perhaps the most radical design ever to emerge from the Yakovlev OKB studio, the VVP-6 appeared more science fiction than a craft likely to have seen production. The VVP-6 was designed as a giant VTOL support platform which would work in coordination with VTOL jets, such as Yakovlev's Yak-38.

Among the many functions envisioned for this line of vehicles was the transportation of food, fuel and munitions. The huge, box-like design was to have been 49m long. In one version it was capable of carrying a complete SAM missile system, including six SA-2 (ASCC name "Guideline") missiles with launchers mounted on the craft's upper surface. Reloads and supporting radars were to be stored internally.

The VVP-6 was to have been fitted with six six-blade rotors mounted on six pylons extending from the craft's sides. Each rotor was to have been driven by four turboshaft engines, giving the VVP-6 a total of 24 engines.

The requirement for such a craft ended when the Soviet Air Force failed to put land-based VTOL jets into service.

See also
Yakovlev Yak-60
Mil V-12

References

 Gunston, Bill. Yakovlev Aircraft since 1924. London, UK: Putnam Aeronautical Books, 1997. .

Abandoned military aircraft projects of the Soviet Union
Military helicopters
Multirotor helicopters
Yak VVP-6
Yakovlev Yak-58. The Yakovlev Yak-58 is a small, multi-role utility transport and business aircraft. The aircraft features a pusher engine and twin boom tail. It saw limited production in the late 1990s.

Design and development
Following the collapse of the Soviet Union, as military contracts evaporated, the Yakovlev design bureau was forced to convert to designing civilian aircraft to stay in business. Their first post-Soviet design was the Yak-58, a small multi-role utility transport designed to appeal to as many prospective buyers as possible.

The Yak-58 is a low-winged monoplane of pusher configuration, powered by a Vedeneyev M14PT radial engine mounted at the rear of the fuselage nacelle, driving a three-bladed propeller. Rather than conventional tailbooms, the two highly swept fins were mounted directly to the wing, and were joined by the tailplane. The undercarriage is a retractable tricycle arrangement. Seats are fitted for a pilot and five passengers, with the option of replacing the passengers by 450 kg (990 kg) of cargo.

Testing
The first prototype made its maiden flight at Tbilisi, Georgia on 26 December 1993, although some sources state that the first flight did not occur until 17 April 1994. This aircraft was wrecked in a fatal crash at the ILA Berlin Air Show on 27 May 1994, with the second prototype flying on 10 October 1994.

Yakovlev claimed in 1997 that it had orders for 250 Yak-58s, with an ELINT version and a version replacing the radial engine with a turboprop planned. Limited production occurred at Tbilisi, however, due to funding problems and political problems between Georgia and Russia, Yakovlev attempted to restart the project in 2003, possibly with production moved back to Russia.

Specifications (Yak-58)

See also

References

Bibliography

 Gordon, Yefim, Dmitry Komissarov and Sergey Komissarov. OKB Yakovlev: A History of the Design Bureau and its Aircraft. Hinkley, UK: Midland Publishing, 2005. .
 Gunston, Bill and Yefim Gordon. Yakovlev Aircraft since 1924. London, UK: Putnam Aeronautical Books, 1997. .
 "ILA '94 Show News: Crash deaths blight Berlin show opening". Flight International, 8–14 June 1994. p. 10.
 Taylor, Michael J. H. Brassey's World Aircraft & Systems Directory 1999/2000 Edition. London: Brassey's, 1999. .

External links
 Official page

1990s Soviet and Russian civil utility aircraft
Yak-058
Single-engined pusher aircraft
Twin-boom aircraft
Low-wing aircraft
Aircraft first flown in 1993
275 kV Forth Crossing. The 275 kV Forth Crossing is an overhead power line crossing of the River Forth in Scotland. The crossing, located next to the Clackmannanshire Bridge and the Kincardine Bridge, has the tallest electricity towers (pylons) in Scotland .

The tower at the southern end is 153.9 metres (505 ft), that at the northern end 137.16 metres (450 ft) tall. The spans are not the same length. One is  425 metres and the other is 462 metres.

See also
 400 kV Thames Crossing
 Aust Severn Powerline Crossing
 Powerline river crossings in the United Kingdom

References

Towers in Scotland
400 kV Forth crossing
Electric power transmission in the United Kingdom
Powerline river crossings
Aurora Subdivision. The Aurora Subdivision or Aurora Sub is a railway line in Wisconsin and Illinois operated by BNSF Railway.  It is part of BNSF's Chicago, Illinois, to Seattle, Washington, Northern Transcon.  This segment runs about  from the St. Croix Subdivision in La Crosse, Wisconsin, to the Chicago Subdivision in Aurora, Illinois.

The original line created by the Chicago, Burlington and Quincy Railroad ran out of Aurora, Illinois to Oregon, Illinois. In 1885, the line was continued from Oregon to connect to St. Paul, Minnesota. From then on, this track hosted some of the fastest trains in the world for the time period, including the Chicago, Burlington and Quincy Railroad's Twin Cities Zephyr.  The Northern Pacific North Coast Limited and Great Northern Empire Builder also ran to Minneapolis–Saint Paul and on to the west coast on this track.  However, with the advent of Amtrak in 1971, the Empire Builder changed its route between Chicago and the Twin Cities to run on the route of the former Milwaukee Road Hiawatha instead.

Today, there is no regular passenger service on the line. However, the line does host occasional passenger trains in the form of excursions or for reroutes of the Empire Builder when necessary. The main freight is intermodal traffic and some freight traffic. Amtrak trains heading westward along the Chicago Subdivision immediately turn southwest toward Galesburg, Illinois, along the Mendota Subdivision as they pass through Aurora, but they currently (as of 2010) do not stop in the city. Metra commuter rail service to Chicago via the BNSF Railway Line terminates at the Aurora Transportation Center, but this is at the end of a spur parallel to the main line. There was an old train station on Broadway (Route 25) about a mile south of the Aurora Transportation Center, but it was demolished in 2013, following damage from a thunderstorm.

The Aurora Subdivision is mostly single track with sidings between Aurora to Plum River, south of Savanna, with the exception of double track from Steward through Rochelle to Flagg Center. At Plum River, it is double track up until it crosses the Wisconsin River near Wyalusing State Park in Wisconsin, where it becomes single track again. The single track continues for a short distance until Crawford, south of Prairie du Chien, where it once again becomes double track to Grand Crossing, where the line becomes the St. Croix Subdivision.

In La Crosse, the branch at Herrington had continued North and West to the Downtown La Crosse Station. It then headed Northeast to re-join the main at a point north of Grand Crossing where the North La Crosse depot still stands today.

References

External links
BNSF Subdivisions

BNSF Railway lines
Rail infrastructure in Illinois
Rail infrastructure in Wisconsin
Columbia River Subdivision. The Columbia River Subdivision or Columbia River Sub is a railway line running about  from Wenatchee to Spokane, Washington. It is operated by BNSF Railway as part of their Northern Transcon. The original line (built in 1893) was built as part of  James J. Hill's Great Northern Railway transcontinental railway line.

Train service 
The Amtrak Empire Builder operates once each way per day along the corridor. Parts of the line see upwards of 40 freight trains a day.

References

External links

BNSF Subdivisions
Online map

BNSF Railway lines
Rail infrastructure in Washington (state)
Railway lines opened in 1893
Gibraltar Artificial Reef. The Gibraltar Artificial Reef, or simply the Gibraltar Reef, is the ongoing artificial reef project for the Mediterranean waters surrounding the British overseas territory of Gibraltar. The initiative was started in 1973 by Dr. Eric Shaw of the Helping Hand Trust.

There are more than 40 dive sites to visit in Gibraltar. Biodiversity is claimed to be high on both natural and artificial reefs.

It consists of a collection of sunken wrecks designed to give marine wildlife an environment to breed and colonise.

The reef project has been the centre of political disagreements between Spain and the UK government.

History
Initially experiments were tried with tyres chained together but sand movement and currents proved to be too strong and washed the tyres away or buried them.  Benthic stones were used but they also suffered from tidal force and proved too expensive. This was followed by sinking of cars and monitoring the effects of sealife upon them, including a Mercedes-Benz that was towed out behind a boat prior to being sunk, driven by diver and instructor Steven Hensaw.

Finally boats and barges were to be donated by the Gibraltar Port Authority and local marinas. These boats were thoroughly cleaned and emptied of all pollutants prior to sinking and every location mapped. The first boats were two barges donated by Gibunco in 1974 and sunk in Camp Bay.

In 2006 the 65 ton wooden boat True Joy, also known as "Noah's Ark", was sunk here. The last major addition was the remains of the MV New Flame, a mid-sized bulk carrier that foundered off Europa Point in 2007.

In 2013 a new type of reef was created by sinking of concrete blocks, with metal spikes attached. This caused a diplomatic row, as Spain claimed that these blocks were ripping fishing nets used for trawling and began discussions of whether to place a tax on visitors into Gibraltar from Spain, and close Spain's airspace for flights inbound to Gibraltar.

Greenpeace commented that "such reefs are a very common practice. This is a diplomatic conflict over maritime sovereignty and not an environmental one." Spain regularly "deployed hundreds of [concrete blocks] to protect its waters" from fishing trawlers.

Diving
Gibraltar's reef has attracted a large variety of marine life, becoming a major attraction for both local and Spanish recreational divers.

See also

References

Further reading
A comparison of the biodiversity between natural and artificial habitats on the coast of Gibraltar. By Hanna-Mari Pekkarinen. Masters Thesis in Marine Ecology, Department of Marine Ecology, Gothenbury University, Sweden. Contribution nr. 210 Date: 16,01,2004
The Gibraltar Artificial Reef. Habitat Manipulation II – Dr Eric Shaw (1996). In: Jornadas de Estudio y Conservation de Flora y Fauna del Campo de Gibraltar, Almoraima 15, pp. 197–204

External links
a  brief history of the A.R. 

Artificial reefs
Environment of Gibraltar
Shipwrecks of Gibraltar
Zinc triflate. Zinc trifluoromethanesulfonate or zinc triflate is the zinc salt of trifluoromethanesulfonic acid. It is commonly used as a Lewis acid catalyst, e.g. in silylations.

A white powder, zinc triflate is commercially available, though some workers have experienced inconsistent results with zinc triflate from different sources. If desired, it may be prepared from reacting trifluoromethanesulfonic acid with zinc metal in acetonitrile, or with zinc carbonate in methanol:

Zn + 2 HOTf → Zn(OTf)2 + H2
ZnCO3 + 2 HOTf → Zn(OTf)2 + H2O + CO2 (OTf = CF3SO3)

References

triflate
Triflates
Acid catalysts
Shock waves in astrophysics. Shock waves are common in astrophysical environments.

Because of the low ambient density, most astronomical shocks are collisionless. This means that the shocks are not formed by two-body Coulomb collisions, since the mean free path for these collisions is too large, often exceeding the size of the system. Such shocks were first theorised by Frederic de Hoffmann and Edward Teller, who studied shock waves in magnetized fluids with infinite conductivity. The precise mechanism for energy dissipation and entropy generation at such shocks is still under investigation, but it is widely accepted that the general mechanism driving these shocks consists of wave particle interaction and plasma instabilities, that operate on the scale of plasma skin depth, which is typically much shorter than the mean free path.

It is known that collisionless shocks are associated with extremely high energy particles, although it has not been definitively established if the high energy photons observed are emitted by protons, electrons or both. The energetic particles are in general believed to be accelerated by the Fermi acceleration mechanism. It is usually agreed that shocks caused by supernova remnants expanding in the interstellar medium accelerate the cosmic rays measured above the Earth's atmosphere.

Shock waves in stellar environments, such as shocks inside a core collapse supernova explosion often become radiation mediated shocks. Such shocks are formed by photons colliding with the electrons of the matter, and the downstream of these shocks is dominated by radiation energy density rather than thermal energy of matter.

An important type of astrophysical shock is the relativistic shock, in which the shock velocity is a non-negligible fraction of the speed of light. These shocks are unique to astrophysical environments, and can be either collisionless or radiation mediated. Relativistic shocks are theoretically expected in gamma ray bursts, active galactic nucleus jets and in some types of supernovae.

Examples
 Interplanetary shock waves due to solar flares and coronal mass ejections, and originally discovered via geomagnetic sudden commencements.
 The bow shocks formed around planets in stellar winds, and sometimes around stars themselves.
 Supernova remnants driving a shock through the interstellar medium (ISM).
 Shocks traveling through a massive star as it explodes in a core collapse supernova.
 Shocks in interstellar gas, caused by a collision between molecular clouds or by a gravitational collapse of a cloud.
 Accretion shocks at the edge of galaxy clusters.

References

Shock waves
Astrophysics
Technical Chamber of Greece. The Technical Chamber of Greece () (TEE-TCG) is the Greek professional organization that serves as the official technical advisor of the Greek state and is responsible for awarding professional licences to all practicing engineers in Greece. It is a public legal entity with elected administration, supervised by the Hellenic Ministry of Environment, Physical Planning and Public Works. The Technical Chamber of Greece is a member of the European Council of Applied Sciences and Engineering.

It was founded in 1923 by the alumni of the National Technical University of Athens.

References

External links
  

Engineering societies based in Greece
1923 establishments in Greece
BPDA. BPDA or biphenyl-tetracarboxylic acid dianhydride is a monomer used in the production of some polyimides.

Applications
Tape automated bonding (TAB), chip on film (COF), lead lock tape, high density flexible printed circuit (FPC), stiffener for FPC, office automation equipment, flexible solar cells, speaker diaphragms (for mobile phones, plasma televisions and car audio, etc.), heavy electric machinery, office automation equipment, thermal control film for satellites, printed circuit boards, metallic substrates, sheet heating elements, heat resistance wires.

Characteristics
 Physical, mechanical, electrical, and chemical properties under high-temperature conditions.
 High tensile strength and modulus, and also features outstanding long-term heat resistance.

Analytics
The chemical shifts in 1H and 13C NMR spectroscopy are given in the literature. The melting point is 299 - 301 °C.

See also
 Polyamide
 UPILEX

References

Monomers
Biphenyls
Carboxylic anhydrides