omniomni/omni-engineering huggingface dataset:
Electrolytic process. An electrolytic process is the use of electrolysis industrially to refine metals or compounds at a high purity and low cost.  Some examples are the Hall-Héroult process used for aluminium, or the production of hydrogen from water.

Overview
Electrolysis is usually done in bulk using hundreds of sheets of metal connected to an electric power source. In the production of copper, these pure sheets of copper are used as starter material for the cathodes, and are then lowered into a solution such as copper sulfate with the large anodes that are cast from impure (97% pure) copper. The copper from the anodes is electroplated on to the cathodes, while any impurities settle to the bottom of the tank. This forms cathodes of 99.999% pure copper.

See also
Electrolysis of water
Electroplating

References

Industrial processes
Chemical processes
Hydrogen production
Articles containing video clips
RasMol. RasMol is a computer program written for molecular graphics visualization intended and used mainly to depict and explore biological macromolecule structures, such as those found in the Protein Data Bank (PDB).

History
It was originally developed by Roger Sayle in the early 1990s.

Historically, it was an important tool for molecular biologists since the extremely optimized program allowed the software to run on (then) modestly powerful personal computers. Before RasMol, visualization software ran on graphics workstations that, due to their cost, were less accessible to scholars. RasMol continues to be important for research in structural biology, and has become important in education.

RasMol has a complex licensing version history. Starting with the version 2.7 series, RasMol source code is dual-licensed under a GNU General Public License (GPL), or custom license RASLIC. Starting with version 2.7.5, a GPL is the only license valid for binary distributions.

RasMol includes a scripting language, to perform many functions such as selecting certain protein chains, changing colors, etc. Jmol and Sirius software have incorporated this language into their commands.

Protein Data Bank (PDB) files can be downloaded for visualization from members of the Worldwide Protein Data Bank (wwPDB). These have been uploaded by researchers who have characterized the structure of molecules usually by X-ray crystallography, protein NMR spectroscopy, or cryogenic electron microscopy.

Interprocess communication
Rasmol can communicate with other programs via Tcl/Tk on Unix platforms, and via Dynamic Data Exchange (DDE) on Microsoft Windows.

With a multiple sequence alignment program, the responsible Java class can be freely used in other applications.

See also

 List of molecular graphics systems
 Comparison of software for molecular mechanics modeling
 Molecular graphics
 Molecule editor
 List of free and open-source software packages

References

External links

Download RasMol (production releases)
Source repository (stable)
Source repository (development)
Early
Later

Molecular modelling software
Free science software
Free software programmed in C
Free educational software
Sangatte. Sangatte (; ) is a commune in the Pas-de-Calais department on the northern coast of France on the English Channel. The name is of Flemish origin, meaning hole or gap in the sand.

Engineering
Sangatte is the location for the Channel Tunnel's French cooling station, its British counterpart being at Samphire Hoe. In addition, it is the French end-point for the HVDC Cross-Channel, the connection between the UK and French electricity grids.

History

First underwater telegraph
Sangatte was the landing point of the world's first operational underwater telegraph cable, laid across the Channel by the Submarine Telegraph Company in 1851 between South Foreland and Sangatte.

Pioneering cross-Channel flight
'Blériot-Plage' is named to commemorate Louis Blériot who, on 25 July 1909, was the first person to fly across the English Channel. He flew from the beach at Sangatte to the White Cliffs of Dover, to claim the prize offered by the Daily Mail. The crossing took 37 minutes in his aeroplane, Blériot XI, built in collaboration with Raymond Saulnier. It was powered by a 3-cylinder  engine.

At the western end of the beach, a statue of the French aviator Hubert Latham overlooks the sea. Latham was another pioneering cross-channel pilot whose earlier attempt on 19 July had failed.

Spitfire
Sangatte is also the landing location of Supermarine Spitfire Mark 1a N3200 of No. 19 Squadron RAF, which was forced to land at the beach after receiving damage to its radiator from shots fired by a Messerschmitt Bf 109 of JG 2 during Operation Dynamo on 26 May 1940, having shot down a Junkers Ju 87 shortly beforehand to protect the evacuating soldiers at Dunkirk. The plane was recovered from the sand at Sangatte in 1986, and restoration work commenced in 2000, which continued until 2014 when works completed, the aircraft having been repaired to a fully airworthy state.

Refugee camp
Sangatte was the location of a refugee camp set up by the French Red Cross in 1999 as a result of an influx of migrants attempting to travel to the United Kingdom. They were mainly from Afghanistan, Iraq and Kosovo. Under pressure from the UK government, Nicolas Sarkozy (then Minister of the Interior), ordered its closure in 2002.  There were riots in 2001 and 2002, the year the camp closed.

Population

Politics

Mayor List

Twin towns

 Sandgate, Kent, England, UK.

In popular culture

In the BBC Two show Top Gear, the three presenters Jeremy Clarkson, Richard Hammond and James May crossed the Channel in an amphibious Nissan Navara and instead of finishing at Calais after leaving Dover, they ended up  along the coast in Sangatte.

Personalities 

 The airmen Hubert Latham and Louis Blériot.
 Fabrice Bourré (born in 1962), French footballer, was born in Blériot-Plage.

See also
 Chinese Labour Corps
 Communes of the Pas-de-Calais département

References

External links

(In French language)

Sangatte sur le site de la Côte d'Opale

Communes of Pas-de-Calais
Calais migrant crisis (1999–present)
Pale of Calais
Populated coastal places in France
AL-6XN. AL-6XN (UNS designation N08367) is a type of weldable stainless steel that consist of an alloy of nickel (24%), chromium (22%) and molybdenum (6.3%) with other trace elements such as nitrogen.

The high nickel and molybdenum contents of the AL-6XN alloy give it good resistance to chloride stress-corrosion cracking. The molybdenum confers resistance to chloride pitting. The nitrogen content serves to further increase pitting resistance and also gives it higher strength than typical 300 series austenitic stainless steels, and thereby often allows it to be used in thinner sections.

This metal is commonly used instead of 300 series stainless steels in high temperature and low pH applications in food processing. For example, tomato juice will corrode 316L stainless steel at pasteurization temperatures of 100 °C (210 °F). AL-6XN will better resist this corrosion while still offering the beneficial properties of stainless steel.

AL-6XN applications and markets  
Applications for superaustenitic stainless steel alloy AL-6XN include chemical processing, oil and gas, medical – sterilization and power generation with specific applications identified in desalination, water piping systems. transformer cases in marine environments, food processing equipment, FGD scrubbers, reverse osmosis, and heat exchangers.

AL-6XN specifications
Specifications include: 

 ASME SA : 182, 240, 249, 312, 479
 ASME SB : 366, 462, 564, 675, 676, 688, 691
 ASTM A : 182, 240, 249, 312, 479
 ASTM B : 366, 462, 472, 564, 675, 676, 688, 691, 804
 NACE : MR0175
 UNS : N08367

References

Chromium alloys
Nickel alloys
Stainless steel
Steel alloys
Modeling and Simulation Coordination Office. The Modeling and Simulation Coordination Office (M&SCO) is an organization within the United States Department of Defense that provides modeling and simulation technology. The M&SCO was named the Defense Modeling and Simulation Office (DMSO) when it was created by Congress in 2006. It was renamed the Modeling and Simulation Coordination Office in late 2007.

The M&SCO leads DoD modeling and simulation standardization efforts. It is the DoD point of contact for coordinating modeling and simulation activities with NATO and Partnership for Peace (PfP) organizations, and provides support to the DoD modeling and simulation management system.

External links
 

United States Department of Defense agencies
Military simulation
Van Arkel–de Boer process. The van Arkel–de Boer process, also known as the iodide process or crystal-bar process, was the first industrial process for the commercial production of pure ductile titanium, zirconium and some other metals. It  was developed by Anton Eduard van Arkel and Jan Hendrik de Boer in 1925 for Philips Nv. Now it is used in the production of small quantities of ultrapure titanium and zirconium. It primarily involves the formation of the metal iodides and their subsequent decomposition to yield pure metal, for example at one of the Allegheny Technologies' Albany plants.

This process was superseded commercially by the Kroll process.

Process
As seen in the diagram below, impure titanium, zirconium, hafnium, vanadium, thorium or protactinium is heated in an evacuated vessel with a halogen at 50–250 °C. The patent specifically involved the intermediacy of TiI4 and ZrI4, which were volatilized (leaving impurities as solid).

At atmospheric pressure TiI4 melts at 150 °C and boils at 377 °C, while ZrI4 melts at 499 °C and boils at 600 °C. The boiling points are lower at reduced pressure. The gaseous metal tetraiodide is decomposed on a white hot tungsten filament (1400 °C). As more metal is deposited the filament conducts better and thus a greater electric current is required to maintain the temperature of the filament. The process can be performed in the span of several hours or several weeks, depending on the particular setup.

Generally, the crystal bar process can be performed using any number of metals using whichever halogen or combination of halogens is most appropriate for that sort of transport mechanism, based on the reactivities involved. The only metals it has been used to purify on an industrial scale are titanium, zirconium and hafnium, and in fact it is still in use today on a much smaller scale for special purity needs.

References

Industrial processes
Zirconium
Dutch inventions
Methods of crystal growth
Titanium processes
Metallurgical processes
Materials science
1925 introductions
20th-century inventions
Parkes process. The Parkes process is a pyrometallurgical industrial process for removing silver from lead during the production of bullion. It is an example of liquid–liquid extraction.

The process takes advantage of two liquid-state properties of zinc. The first is that zinc is immiscible with lead, and the other is that silver is 3000 times more soluble in zinc than it is in lead. When zinc is added to liquid lead that contains silver as a contaminant, the silver preferentially migrates into the zinc. Because the zinc is immiscible in the lead it remains in a separate layer and is easily removed. The zinc-silver solution is then heated until the zinc vaporizes, leaving nearly pure silver. If gold is present in the liquid lead, it can also be removed and isolated by the same process.

The process was patented by Alexander Parkes in 1850. Parkes received two additional patents in 1852.

The Parkes process was not adopted in the United States, due to the low native production of lead. The problems were overcome during the 1880s and by 1923 only when the Parkes process was used.

See also 
Lead smelter
Pattison's Process
Patio process

References 

Lead
Silver
Metallurgical processes
Reality Lab. Reality Lab was a 3D computer graphics API created by RenderMorphics to provide a standardized interface for writing games. It was one of the main contenders in the realtime 3D middleware marketplace at the time, alongside Criterion Software's RenderWare and Argonaut Software's BRender.

Reality Lab was a scene graph API providing real-time rendering that would run with acceptable performance on graphics cards or the host computer's CPU.

Founded in 1992 by Servan Keondjian, Doug Rabson and Kate Seekings, RenderMorphics was purchased by Microsoft in February 1995 and Reality Lab formed the basis for Direct3D. Microsoft's acquisition statement of RenderMorphics contained a description of Reality Lab:

Architecturally Reality Lab was then separated into a low layer immediate mode API and layered upon it the original scene graph API which was afterwards called retained mode API. Direct3D shipped for the first time in the DirectX 2.0 SDK in June 1996.

See also
Qube Software
Glide

References

  Covers the early years of DirectX development within Microsoft, including the acquisition of RenderMorphics.

DirectX
CAP computer. The Cambridge CAP computer was the first successful experimental computer that demonstrated the use of security capabilities, both in hardware and software. It was developed at the University of Cambridge Computer Laboratory in the 1970s. Unlike most research machines of the time, it was also a useful service machine.

The sign currently on the front of the machine reads:
The CAP project on memory protection ran from 1970 to 1977. It was based on capabilities implemented in hardware, under M. Wilkes and R. Needham with D. Wheeler responsible for the implementation. R. Needham was awarded a BCS Technical Award in 1978 for the CAP (Capability Protection) Project.

Design
The CAP was designed such that any access to a memory segment or hardware required that the current process held the necessary capabilities.

The 32-bit processor featured microprogramming control, two 256-entry caches, a 32-entry write buffer and the capability unit itself, which had 64 registers for holding evaluated capabilities. Floating point operations were available using a single 72-bit accumulator. The instruction set featured over 200 instructions, including basic ALU and memory operations, to capability- and process-control instructions.

Instead of the programmer-visible registers used in Chicago and Plessey System 250 designs, the CAP would load internal registers silently when a program defined a capability. The memory was divided into segments of up to 64K 32-bit words. Each segment could contain data or capabilities, but not both. Hardware was accessed via an associated minicomputer.

All procedures constituting the operating system were written in ALGOL 68C, although a number of other closely associated protected procedures  - such as a paginator - are written in BCPL.

Operation
The CAP first became operational in 1976. A fully functional computer, it featured a complete operating system, file system, compilers, and so on. The OS used a process tree structure, with an initial process called the "Master coordinator". This removed the need for separate modes of operation, as each process could directly access the resources of its children. In practice, only two levels were ever used during the CAP's operation.

In 1981 the MACRO SPITBOL version of the SNOBOL4 programming language was implemented on the CAP by Nicholas J. L. Brown.

See also

Plessey System 250
IBM System/38
C.mmp
RSRE Flex

Notes

References 
 
 

Computers designed in the United Kingdom
Capability systems
One-of-a-kind computers
University of Cambridge Computer Laboratory
Synchronous circuit. In digital electronics, a synchronous circuit is a digital circuit in which the changes in the state of memory elements are synchronized by  a clock signal.  In a sequential digital logic circuit, data is stored in memory devices called flip-flops or latches.  The output of a flip-flop is constant until a pulse is applied to its "clock" input, upon which the input of the flip-flop is latched into its output.    In a synchronous logic circuit, an electronic oscillator called the clock generates a string (sequence) of pulses, the "clock signal".  This clock signal is applied to every storage element, so in an ideal synchronous circuit, every change in the logical levels of its storage components is simultaneous. Ideally, the input to each storage element has reached its final value before the next clock occurs, so the behaviour of the whole circuit can be predicted exactly.  Practically, some delay is required for each logical operation, resulting in a maximum speed limitations at which each synchronous system can run.

To make these circuits work correctly, a great deal of care is needed in the design of the clock distribution networks.  Static timing analysis is often used to determine the maximum safe operating speed.

Nearly all digital circuits, and in particular nearly all CPUs, are fully synchronous circuits with a global clock.
Exceptions are often compared to fully synchronous circuits.
Exceptions include self-synchronous circuits,
globally asynchronous locally synchronous circuits,
and fully asynchronous circuits.

See also
 Synchronous network
 Asynchronous circuit
 Moore machine
 Mealy machine
 Finite-state machine
 Sequential logic
 Memory
 Control unit
 Arithmetic logic unit
 Processor register
 Application-specific integrated circuit (ASIC)

References 

Automata (computation)
Clock signal
Flight spare. A flight spare is a copy of a spacecraft or spacecraft part which is held in reserve in case it is needed for the mission. Flight spares are built to the same specifications as the original equipment (the "flight model"), and can be substituted in the case of damage or other problems with the flight model, reducing launch delays. The extra cost of building a flight spare can be justified by the enormous cost of delaying a launch by even a short amount of time.

Primary function

Flight spares are constructed as contingencies. As such, spare parts may be swapped onto a craft before launch, or completed spare spacecraft may be launched if the flight model is lost.

NASA has two basic types of spares, development spares and operational spares.  NASA makes a determination about which parts need spares based on whether parts are custom built, and the lead-time for procurement. It also makes determinations about the quantities of spares, based on whether the part is critical to system operation, failure rate, and the expected life of the part.

The flight spare can also be useful during a space mission if a change to the original plan is required, since the effect of changes can be safely tested on the ground.

Reusage

Flight spares that go unused in their initial missions are still considered valuable. A 2017 NASA report on flight spare inventory control mentions hundreds of millions of dollars' worth of inventory, not all of it catalogued properly.

New missions for old hardware

Individual spare components manufactured for one mission may eventually fly on another. As a cost-saving measure, the Magellan spacecraft was made largely out of such parts:

Reuse type legend

Flight spares on display

Since few space probes return to Earth intact, flight spares are useful for posterity, and may go to museums. The Mariner 10 flight spare is such an example.

References

See also 

 Orbit Replaceable Units
 Spare part

Spacecraft components
Anicut. An anicut (Originated from Tamil language  அணைக்கட்டு - Aṇaikaṭṭu and Kannada language ಆಣೆಕಟ್ಟು - Āṇekaṭṭu) and also in Telugu language as ఆనకట్ట - ÃnaKaṭṭa, is a masonry check dam that is constructed across a stream to impound water for maintaining and regulating irrigation. The water stored behind an anicut can be used for irrigation of crops or drinking water for humans and livestock. They also are used to increase the residence of water to recharge groundwater, especially wells located downstream. Anicuts are also used in wildlife sanctuaries to provide sufficient water hole for will animals or to provide habitats for aquatic flora and fauna.

Construction 
The selection of an appropriate site for construction is very important as to minimize cost and maximize efficacy. The site should be where maximum storage of water is possible with minimum dam length, such as a deep, narrow section of a valley with steep slopes. Anicuts require a stream gradient of more than 1:100.

References 

Masonry dams
HAECO. Hong Kong Aircraft Engineering Company Limited (HAECO) is an aircraft engineering and maintenance firm with its head office located at Hong Kong International Airport. It is a member of the Swire Group.

References

External links
HAECO Group Website

Swire Group
Aircraft engineering companies
Aerospace companies of Hong Kong
Former companies in the Hang Seng Index
Engineering companies of Hong Kong
Companies based in Greensboro, North Carolina
1950 establishments in Hong Kong
Newman projection. A Newman projection is a drawing that helps visualize the 3-dimensional structure of a molecule. This projection most commonly sights down a carbon-carbon bond, making it a very useful way to visualize the stereochemistry of alkanes. A Newman projection visualizes the conformation of a chemical bond from front to back, with the front atom represented by the intersection of three lines (a dot) and the back atom as a circle. The front atom is called proximal, while the back atom is called distal. This type of representation clearly illustrates the specific dihedral angle between the proximal and distal atoms. 

This projection is named after American chemist Melvin Spencer Newman, who introduced it in 1952 as a partial replacement for Fischer projections, which are unable to represent conformations and thus conformers properly. This diagram style is an alternative to a sawhorse projection, which views a carbon–carbon bond from an oblique angle, or a wedge-and-dash style, such as a Natta projection. These other styles can indicate the bonding and stereochemistry, but not as much conformational detail.

A Newman projection can also be used to study cyclic molecules, such as the chair conformation of cyclohexane:

Because of the free rotation around single bonds, there are various conformations for a single molecule. Up to six unique conformations may be drawn for any given chemical bond. Each conformation is drawn by rotation of either the proximal or distal atom 60 degrees. Of these six conformations, three will be in a staggered conformation, while the other three will be in an eclipsed conformation. These six conformations can be represented in a relative energy diagram. 

A staggered projection appears to have the surrounding species equidistant from each other. This kind of conformation tends to experience both anti and gauche interactions. Anti interactions refer to the molecules (usually of the same type) sitting exactly opposite of each other at 180° on the Newman projection. Gauche interactions refer to molecules (also usually of the same type) being 60° from each other on a Newman projection. Anti interactions experience less steric strain than gauche interactions, but both experience less steric strain than the eclipsed conformation.

An eclipsed projection appears to have the surrounding species almost on top of each other. In reality, these species are in line with each other, but are drawn slightly staggered to help format the projection onto paper. These types of conformations are generally higher in energy due to increased bond strain. However, this strain can be somewhat lower if a hydrogen is eclipsed over a larger species, as opposed to two large species eclipsed over each other.

See also

Haworth projection
Fischer projection
Natta projection
Stereochemistry

References