omniomni/omni-engineering huggingface dataset:
Austinite. Austinite is a member of the adelite-descloizite group, adelite subgroup, the zinc (Zn) end member of the copper-Zn series with conichalcite. It is the zinc analogue of cobaltaustinite and nickelaustinite. At one time “brickerite” was thought to be a different species, but it is now considered to be identical to austinite. Austinite is named in honour of Austin Flint Rogers (1877–1957), American mineralogist from Stanford University, California, US.

Structure

The structure is composed of chains of edge-sharing polyhedra ZnO6, and very distorted Ca(O,OH)8 polyhedra linked through AsO4 into a three-dimensional network.

Any crystal which has a mirror plane as one of its symmetry elements has the property that its mirror image (with any plane as the mirror plane) can always be superimposed on the original crystal by translation or rotation or both. If there are no mirror planes as symmetry elements then the mirror image of a crystal cannot be brought into superposition with the original crystal by rotation or translation. This is enantiomorphism, and the mirror images are said to be enantiomorphs of each other. The possibility of enantiomorphic crystals is determined by the crystal symmetry, i.e., by the point group of the crystal species. There are 32 possible point groups, and 22 of these are capable of forming enantiomorphs. The enantiomorphs are designated right or left handed, according to whether they rotate the plane of polarised light to the right or to the left. Sometimes it is clear from the outward form of the crystal whether it is right or left handed, and sometimes optical methods are needed to determine this.

The commonest enantiomorphic mineral is quartz, with point group 32; all quartz crystals will be either right or left handed, but it may not be possible to distinguish this from the external form unless some critical crystal faces are present.

Austinite has point group 222, with no mirror planes, so austinite is also an enantiomorphic mineral, occurring as both right handed and left handed crystals, with right handed ones more common.

Occurrence
Austinite is a rare mineral in the oxidation zone of arsenic bearing base metal deposits, where it is found developed on the colloform (pertaining to the rounded, globular texture of mineral formed by colloidal precipitation) surface of limonite or lining small cavities. It is closely associated with adamite, and appears to be a later mineral. Austinite is associated with adamite, quartz, talmessite and limonite. Its type locality is Gold Hill Mine (Western Utah Mine), Gold Hill, Gold Hill District (Clifton District), Deep Creek Mts, Tooele County, Utah, United States.

References

Arsenate minerals
Orthorhombic minerals
Minerals in space group 19
Brickworks. A brickworks, also known as a brick factory, is a factory for the manufacturing of bricks, from clay or shale. Usually a brickworks is located on a clay bedrock (the most common material from which bricks are made), often with a quarry for clay on site. In earlier times bricks were made at brickfields, which would be returned to agricultural use after the clay layer was exhausted.

Equipment

Most brickworks have some or all of the following:
A kiln, for firing, or 'burning' the bricks.
Drying yard or shed, for drying bricks before firing.
A building or buildings for manufacturing the bricks.
A quarry for clay.
A pugmill or clay preparation plant (see below).

Brick making

Bricks were originally made by hand, and that practice continues in developing countries and with a few specialty suppliers.
Large industrial brickworks supply clay from a quarry, moving it by conveyor belt or truck/lorry to the main factory, although it may be stockpiled outside before entering the machinery. When the clay enters the preparation plant (Clay Prep) it is crushed, and mixed with water and other additives which may include breeze, a very fine anthracite that aids firing.
This process, also known as pugmilling, improves the consistency, firing qualities, texture, and colour of the brick. From here, the processed clay can either be extruded into a continuous strip and cut with wires, or be put into  moulds or presses (also referred to as forming) to form the clay into its final shape. 
After the forming or cutting, the bricks must be dried - in the open air, in drying sheds, or in special drying kilns.  The dried bricks must then be fired or "burnt" in a kiln, to give them their final hardness and appearance.

In the mid-nineteenth century the development of automated brickmaking machines such as the Bradley & Craven Ltd "Stiff-Plastic Brickmaking Machine" revolutionised the brick-manufacturing process.

, one of the largest single brickworks site in the world able to manufacture one million bricks per day stands on the banks of the Swan River in Perth in Western Australia.

Environmental effects
Zigzag brick kilns are recommended over traditional brick kilns because they consume less coal.

Historical notes
In the past, clay was often transported from the quarry to the brickworks by narrow gauge railway or aerial ropeway.

Notable brickworks
 The London Brick Company
 Bursledon Brickworks
Brickworks Limited - Australian brick manufacturer
Evergreen Brickworks

See also

References

 
.
Molding processes
Manufacturing plants
Bricks
Firing techniques
Pyrotechnic colorant. A pyrotechnic colorant is a chemical compound which causes a flame to burn with a particular color. These are used to create the colors in pyrotechnic compositions like fireworks and colored fires. The color-producing species are usually created from other chemicals during the reaction. Metal salts are commonly used; elemental metals are used rarely (e.g. copper for blue flames).

The color of the flame is dependent on the metal cation; the anion of the salt has very little direct influence. The anions however influence the flame temperature, both by increasing it (e.g. nitrates, chlorates) and decreasing it (e.g. carbonates, oxalates), indirectly influencing the flame brightness and brilliancy. For temperature-decreasing additives, the limit of colorant may be about 10–20 wt.% of the composition.

Some common examples are:

Radiating species
Despite the wide numbers of metal ion donors, they serve to form only a few atomic and molecular species that are useful as light emitters.

In many cases, chlorine donors have to be added in order to achieve sufficiently deep colors, as the desired emitting molecules have to be generated.

Some color emitters are of atomic nature (e.g. lithium, sodium). Presence of chlorine, and the reaction to monochlorides, may actually impair their color purity or intensity.

At high temperatures, the atoms will ionize. The emission spectra of ions are different than of neutral atoms; the ions may emit in undesired spectral ranges. For example, Ba+ emits in blue wavelengths. Ionization can be suppressed by addition of an easier-to-ionize metal with weak visible emission of its own, e.g. potassium; the potassium atoms then act as electron donors, neutralizing the barium ions.

The color blue is notoriously difficult to produce in fireworks, as the copper compounds need to be heated at a specific temperature for the optimal shade of blue to be produced. Thus, a deep, rich blue is usually viewed as the mark of an experienced fireworks maker.

Care should be taken to avoid formation of solid particles in the flame zone, whether metal oxides or carbon; incandescent solid particles emit black-body radiation that causes "washing out" of the colors. Addition of aluminium raises the flame temperature but also leads to formation of solid incandescent particles of aluminium oxide and molten aluminium. Magnesium has less such effect and is therefore more suitable for colored flames; it is more volatile than aluminium and more likely to be present as vapors than as particulates. Formation of solid particles of magnesium oxide can further be inhibited by presence of carbon monoxide, either by negative oxygen balance of the composition in presence of organic fuels, or by addition of the colorant in the form of an oxalate, which decomposes to carbon dioxide and carbon monoxide; the carbon monoxide reacts with the magnesium oxide particles to gaseous magnesium and gaseous carbon dioxide.

See also

 Environmentally friendly red light flare

References

External links
Claude Lajeunesse. Claude Lajeunesse (born 1941) is a Canadian engineer and corporate executive. Since 30 November 2007, he has been the president and chief executive officer of the Aerospace Industries Association of Canada. He is the former president and vice-chancellor of Concordia University in Quebec.

Career
Claude Lajeunesse was born in Quebec City, received a Master of Science degree in 1967 in Nuclear Engineering and a PhD in 1969. He is a member of the boards of TD Meloche Monnex, Atomic Energy of Canada Limited, the Montreal Board of Trade, and the Canadian Liver Foundation, a Fellow of the Canadian Academy of Engineering, and a member of the Ordre des ingénieurs du Québec.

From 1995 until August 2005, Lajeunesse was president and vice chancellor of Ryerson University. Prior to this, he was CEO of the Association of Universities and Colleges of Canada. He was appointed to serve a five-year term as the president and vice-chancellor of Concordia University in Montreal beginning 1 August 2005, but left this post on 31 October 2007 due to conflicts with the Concordia board of governors.

Criticism and public perception
Lajeunesse has been criticized for "corporatization" of the universities he has headed by emphasizing part-time labor, raising tuition fees, and union busting.

At both Ryerson and Concordia, Lajeunesse's first acts included giving himself a 50% pay raise, and increases of 20-50% for his immediate entourage. Lajeunesse defended these changes as bringing parity with other universities in Canada. However, unions were critical, as their membership had gone without wage increases for five years, and the university's offer of a 2.5% increase did not address parity or even the cost of living increase.

References

 
 
 Concordia News : Claude Lajeunesse appointed President of Concordia University (2005)
 Concordia News : Claude Lajeunesse steps down as President of Concordia University (2007)
 The Eye Opener (Ryerson University): Bye, Claude. You won't be missed (2007)
 The Eye Opener (Ryerson University): Ex-Rye head resigns from Concordia (2007)
 The Link (Concordia University): Concordia university president resigns (2007)
 The Link (Concordia University): Faculties demand answers about Concordia president’s resignation (2007)
 Macleans's : Leaving Concordia (2007)

Notes

Citations

External links
Claude Lajeunesse Biography

Living people
Presidents of Toronto Metropolitan University
Presidents of Concordia University
1941 births
People from Quebec City
Fellows of the Engineering Institute of Canada
Canadian university and college chief executives
Rectiformer. A rectiformer is a rectifier and transformer designed and built as a single entity for converting alternating current into direct current. It is piece of power systems equipment rather than an electronics component.  Rectiformers are used for supplying power to different field of ESP (electrostatic precipitator).  Rectiformers are also used to create DC supply for Hall process cells in the aluminium smelting industry.

Rectiformers are commonly found in electrowinning operations, where a direct current is required to convert base metal ions such as copper to a metal at the cathode. The passage of an electric current through a purified copper sulfate solution produces cathode copper. The equation is as follows:

Cu2+aq+ 2e− = Cuo

Physical characteristics
Rectiformers may be designed to output voltages from 30V to over 120KV dc and can weigh over 400 tons.

See also 
 Power inverter

References

External links
 Document describing rectiformer substation installation

Electrical components
Hill descent control system. Hill descent control (HDC, or hill mode descent control) is a driver-assistance system allowing for a controlled hill descent in rough terrain without any brake input from the driver.

Overview
A vehicle can perform controlled descent using the anti-lock braking system (ABS) and in some cases engine braking. If a vehicle accelerates under the force of gravity, the system will automatically apply brakes to slow down to the desired vehicle speed. Cruise control buttons can adjust the speed on some vehicles. Applying pressure to the accelerator or brake pedal will override the HDC system. Later implementations combine HDC with traction control and low-range gears and have reduced the set speed to slower than walking pace for extra control.

History
Land Rover invented HDC in late 2002 by adding it to the now discontinued Freelander.

References

Advanced driver assistance systems
Anacron. anacron is a computer program that performs periodic command scheduling, which is traditionally done by cron, but without assuming that the system is running continuously.  Thus, it can be used to control the execution of daily, weekly, and monthly jobs (or anything with a period of n days) on systems that don't run 24 hours a day.  anacron was originally conceived and implemented by Christian Schwarz in Perl, for the Unix operating system. It was later rewritten in C by Itai Tzur; maintainers have included Sean 'Shaleh' Perry and Pascal Hakim.

Since 2009, Red Hat's cron implementation, cronie, has included anacron. Since then, anacron has been updated by Red Hat as a part of cronie.

Advantages 
Unix systems commonly run "housekeeping chores" such as log rotation, unused files deletion, indexing local files for the search engine, sending disk usage reports, etc. A program called cron may be used to schedule these tasks.

With cron, tasks are commonly scheduled to be executed when the system is expected to be idle. If the system is off at the moment a task should be run, it will not be executed. Anacron is different and moves tasks to different moments so they are run when the system is on and utilising cron.

Disadvantages 
Only the system administrator can configure anacron tasks. In contrast, cron allows non-admin users to configure scheduled tasks. If necessary, a non-admin user can use the at Unix command to request a scheduled task (which is guaranteed to run). Upon starting, this command can then automatically request to run itself at a future date, thus giving the appearance of a regularly scheduled task, with guaranteed execution.

anacron can run tasks only once a day (or less often such as weekly or monthly). In contrast, cron allows tasks to run as often as every minute (but does not guarantee their execution if the system goes down). In practice, this is not usually an issue, since it is rare to have a task that must be guaranteed to run more often than (at least) once a day — especially on a system that is not necessarily running at all times.

If the system is rebooted or started after midnight, the daily tasks are run after a user-specified delay in synchronized fashion (sequential order), so only one anacron-task is running at a time. When that task is finished, the next one starts and so on.

This behaviour can be overridden to allow concurrent (parallel) tasks, but can consume system resources that are needed by the user to do work. In contrast, cron will only run daily tasks at the time set (e.g. in the middle of the night, when presumably the machine is not being used).

fcron is another implementation of cron, which attempts to fulfill the roles of both Vixiecron and anacron.

See also 
 List of Unix commands
 Cron

References

External links 
 anacron on SourceForge
 anacron(8) – Linux Programmer's Manual
fcron

Unix process- and task-management-related software
Phillipsite. Phillipsite is a mineral series of the zeolite group; a hydrated potassium, calcium and aluminium silicate, approximating to . The members of the series are phillipsite-K, phillipsite-Na and phillipsite-Ca. The crystals are monoclinic, but only complex cruciform twins are known, these being exactly like twins of harmotome which also forms a series with phillipsite-Ca. Crystals of phillipsite are, however, usually smaller and more transparent and glassy than those of harmotome. Spherical groups with a radially fibrous structure and bristled with crystals on the surface are not uncommon. The Mohs hardness is 4.5, and the specific gravity is 2.2. The species was established by Armand Lévy in 1825 and named after William Phillips. French authors use the name Christianite (after Christian VIII of Denmark), given by A. Des Cloizeaux in 1847.

Phillipsite is a mineral of secondary origin, and occurs with other zeolites in the amygdaloidal cavities of mafic volcanic rocks: for example in the basalt of the Giants Causeway in County Antrim, and near Melbourne in Victoria; and in Lencitite near Rome. Small crystals of recent formation have been observed in the masonry of the hot baths at Plombires and Bourbonne-les-Bains, in France. Minute spherical aggregates embedded in pelagic red clay were dredged by the Challenger from deep sea sedimentary deposits in the Pacific Ocean.

It has been discovered that the volcanic ash that Romans employed in the mix for construction of harbor piers and sea walls contained phillipsite, and that an interaction with sea water actually causes crystalline aluminous tobermorite structures in the mortar to expand and strengthen, making the material substantially more durable than modern concrete.

See also
List of minerals
List of minerals named after people
Roman Concrete

References

External links
Structure type PHI

Calcium minerals
Sodium minerals
Potassium minerals
Aluminium minerals
Zeolites
Monoclinic minerals
Minerals in space group 11
Crystal Mill. The Crystal Mill, or the Old Mill is an 1892 wooden powerhouse located on an outcrop above the Crystal River in Crystal, Colorado, United States.  It is accessible from Marble, Colorado via four-wheel drive.  Although called a Watermill, it is more correctly denoted as a compressor station, which used a water turbine to drive an air compressor, and was originally built with a horizontal wheel. The compressed air was then used to power other machinery or tools.

Names
In the 21st century, the mill is usually called the Crystal Mill or the Old Crystal Mill.  Many decades ago, when the mill was still in use, it was called the Sheep Mountain Power House at the Lost Horse Millsite, or simply the Lost Horse Mill. The building is built on a mining claim named "Lost Horse". The site is referred to as a "mill" because there was a 3-stamp mill for crushing ore, in a building directly adjacent to the south of the surviving structure.

History
The mill was constructed in 1893 by George C. Eaton and B.S. Phillips, promoters of the Sheep Mountain Tunnel and Mining Company. It was built as a power plant for the Sheep Mountain Tunnel. Originally it had a horizontal waterwheel that generated compressed air for miners in the nearby silver mines.  It fell into disuse in 1917 when the Sheep Mountain Tunnel mine closed. The mill was placed on the National Register of Historic Places on July 5, 1985.

See also
National Register of Historic Places listings in Gunnison County, Colorado

References

External links

Directory of Colorado State Register Properties

Gallery

Industrial buildings and structures in Colorado
Buildings and structures in Gunnison County, Colorado
Industrial buildings and structures on the National Register of Historic Places in Colorado
Tourist attractions in Gunnison County, Colorado
Watermills in the United States
National Register of Historic Places in Gunnison County, Colorado
Rigid Raider. The Rigid Raider (RRC) is a series of fast raiding and assault craft made by RTK Marine, a subsidiary of Halmatic, part of BAE Systems Surface Ships. They are primarily in service with two branches of the British Armed Forces: The Royal Navy (incl. the Royal Marines and the Special Boat Service) and the British Army. Despite being among the smallest of the amphibious craft, the RRC is one of the most widely used due to its mobility and versatility. As such, the Rigid Raider often finds itself deployed in amphibious and riverine operations around the globe, in environments ranging from the Arctic to the tropics.

Specifications
The Rigid Raider Mk3 has the following specifications:
Hull: Glass-reinforced plastic
Weight (full): 2,500 kg (2.5 tonnes)
Length: 
Width: 
Engine: 6-cylinder turbo-diesel, 
Speed (full): 
Range: In excess of 
Troops: 10 Royal Marines (2 crew, 8 fully equipped troops)
Number in service: 50 as of 2023

There is also a larger 8 meter version of the RRC in service with the Royal Navy and Royal Marines.

See also
List of active Royal Marines military watercraft

References

External links
Royal Marines - Landing Craft (royalnavy.mod.uk)

Amphibious warfare vessels of the United Kingdom
Landing craft
British Army equipment
Royal Marines
Military boats
August von Parseval. August von Parseval (5 February 1861, in Frankenthal (Pfalz) – 22 February 1942, in Berlin) was a German airship designer. His designs for an amphibian flying boat, balanced by two wing-floats, achieved liftoff in April 1910. This marked the beginning of marine aviation in Germany. He became a professor at the Technical University of Berlin.

As a boy, Parseval attended the Royal Bavarian Pagenkorps in Munich from 1873 to 1878, where he took the Fähnrichexamen (cadet exams). He then joined the Royal Bavarian 3rd Infantry Regiment Prinz Carl von Bayern. An autodidact, he busied himself with the problems of aeronautics. In the garrison town of Augsburg he came into contact with August Riedinger and also came to know his later partner , with whom he developed Drachenballons: kite balloons used by the military for observation designated as Parseval-Sigsfeld type.

In 1901 Parseval and Sigsfeld began building a dirigible airship. After Sigsfeld's death during a free balloon landing in 1902, the work was interrupted until 1905.

By 1905, thanks to improvements in motor design, an appropriate engine was now available. His designs were licensed to the British Vickers company. In 1907, Parseval retired from the Germany army to devote his time entirely to scientific works. His partner von Sigsfeld had died in 1906. 

Up to the end of the First World War, 22 Parseval airships (both non-rigid (blimps) and semi-rigid (with keels) were built. In the late twenties and early thirties, four more semi-rigid airships were built in accordance with the "Parseval-Naatz principle". Because the Parseval ships were non-rigid, unlike Zepplins, they were sold freely to foreign powers, including: Asutria, Russia, Turkey, Japan, Italy, and Great Britain.

Parseval is sometimes written Parzeval or Parceval, particularly in historical documents.

The flights of each 'Parseval', like those of the Zeppelins, excited great interest. In Kiel, a tavern closed in 2002 which had been named Zum Parseval upon the first visit of one of these airships in 1912.

See also
Parseval airships

References

External links

 
 "The Latest Developments in Dirigible Balloons" by Major August von Parseval in the 1912 bulletin by the Aero Club of America
Tabellarischer Lebenslauf (German)
 

1861 births
1942 deaths
People from Frankenthal
People from the Palatinate (region)
German airship aviators
Airships of Germany
Academic staff of Technische Universität Berlin