omniomni/omni-engineering huggingface dataset:
Phyllite. Phyllite ( ) is a type of foliated metamorphic rock formed from slate that is further metamorphosed so that very fine grained white mica achieves a preferred orientation. It is primarily composed of quartz, sericite mica, and chlorite.

Phyllite has fine-grained mica flakes, whereas slate has extremely fine mica flakes, and schist has large mica flakes, all mica flakes of which have achieved a preferred orientation. Among foliated metamorphic rocks, it represents a gradation in the degree of metamorphism between slate and schist.

The minute crystals of graphite, sericite, or chlorite, or the translucent fine-grained white mica, impart a silky, sometimes golden sheen to the surfaces of cleavage, called "phyllitic luster".

The word comes from the Greek phyllon, meaning "leaf".

The protolith (or parent rock) for phyllite is shale or pelite; or slate, which in turn came from a shale protolith. Its constituent platy minerals are larger than those in slate but are not visible with the naked eye. Phyllites are said to have a texture called "phyllitic sheen," and are usually classified as having formed through low-grade metamorphic conditions through regional metamorphism metamorphic facies.

Phyllite has good fissility (a tendency to split into sheets). Phyllites are usually black to gray or light greenish gray in color. The foliation is commonly crinkled or wavy in appearance. Phyllites are mostly used in decorative aggregates, interior decors, building stones, facing stones, garden decoration and curbing. Cemetery markers, commemorative tablets, creating artworks and writing slates are some of its commercial uses.

Phyllite is commonly found in the Dalradian metasediments of northwest Arran. In north Cornwall, there are Tredorn phyllites and Woolgarden phyllites.

Carolina "slate" is often volcanic phyllite. A type of Carolina slate,  Duke stone, is a dacitic phyllite that is fractured and colored with iron oxide.

References

External links

Metamorphic rocks
Edward B. Ellington. Edward Bayzand Ellington (2 August 1845 – 10 November 1914) was a British hydraulic engineer who pioneered the development of urban-scale hydraulic power distribution systems.

Ellington was managing director of the Hydraulic Engineering Co of Chester and one of the founders of the London Hydraulic Power Company.  He invented the hydraulic balance lift (US: elevator) and the automatic injector fire hydrant.

Early life
The second son of a warehouseman, Ellington was born in Camberwell, and studied at Denmark Hill Grammar School before being articled to the Greenwich-based maritime engineering firm of John Penn in 1862.

In 1869, he left Penn's company and London and entered into partnership with Bryan Johnson of Chester; Johnson and Ellington specialised in hydraulic machinery. In 1871, they established the Wharves and Warehouses Steam Power and Hydraulic Pressure Company. In 1875, the partnership converted to a limited company, the Hydraulic Engineering Co.

Hydraulic power

Two years later, in 1877, Ellington was engineer to the Hull Hydraulic Power Co., the first company to demonstrate the practicability of large-scale urban hydraulic power networks, in Kingston upon Hull.

In London in 1882, he was consulting engineer to the General Hydraulic Power Company of Southwark (incorporated 29 June), and, in 1884, helped form its subsidiary, the London Hydraulic Power Company, which merged the Wharves and Warehouses Steam Power and Hydraulic Pressure Company and the General Hydraulic Power Company. This was followed by similar UK companies in Liverpool (Liverpool Hydraulic Power Company, 1889), Manchester (Manchester Hydraulic Power, 1894) and Glasgow (1895), plus Australian schemes in Melbourne (1889) and Sydney (1891). The emergence of electrical power during the 20th century meant hydraulic networks were gradually superseded; the Hull company was wound up in 1947 while the final London pumping station ceased operation in 1977.

Late in his life Ellington was elected President of the Institution of Mechanical Engineers. He died at his London home (73 Addison Road, Kensington) on 10 November 1914.

Family
Ellington married Marion Florence Leonard, and they had at least one child, a son, Edward Ellington (born in Kensington in 1877), who became a senior figure in the Royal Air Force.

Notes and references

External links
 

1845 births
1914 deaths
Hydraulic engineers
T (programming language). T is a dialect of the Scheme programming language developed in the early 1980s by Jonathan A. Rees, Kent M. Pitman, and Norman I. Adams of Yale University as an experiment in language design and implementation.

Rationale
T's purpose is to test the thesis developed by Guy L. Steele Jr. and Gerald Jay Sussman in their series of papers about Scheme: that Scheme may be used as the basis for a practical programming language of exceptional expressive power, and that implementations of Scheme could perform better than other Lisp systems, and competitively with implementations of programming languages, such as C and BLISS, which are usually considered to be inherently more efficient than Lisp on conventional machine architectures. Much of this occurs via an optimizing compiler named Orbit.

T contains some features that modern Scheme lacks. For example, T is object-oriented, and it has first-class environments, called locales, which can be modified non-locally and used as a module system. T has several extra special forms for lazy evaluation and flow control, and an equivalent to Common Lisp's setf. T, like Scheme, supports call-with-current-continuation (call/cc), but it also has a more limited form called catch. From the T manual, a hypothetical implementation of cons could be:

 (define-predicate pair?)
 (define-settable-operation (car pair))
 (define-settable-operation (cdr pair))
 (define (cons the-car the-cdr)
         (object nil
                 ((pair? self) t)
                 ((car self) the-car)
                 ((cdr self) the-cdr)
                 (((setter car) self new-car) (set the-car new-car))
                 (((setter cdr) self new-cdr) (set the-cdr new-cdr))))

This example shows that objects in T are intimately related to closures and message-passing. A primitive called join puts two objects together, allowing for something resembling inheritance.

Ports
T was ported to many hardware platforms and operating systems, including:

MIPS: DEC 3100 (pmax), SGI IRIS
Motorola 68000 (m68k): Apollo Domain/OS, HP/UX, Mac/AUX, NeXT, SunOS 3
NS320xx (n32k): Encore Multimax
SPARC: SunOS 4 and above, Solaris, Unix on Connection Machine 5
VAX: Ultrix

See also

References

External links
 
 History of T, by Olin Shivers
 T manual (PDF) from ReadScheme, via the Internet Archive

Lisp programming language family
Scheme (programming language)
Programming languages created in 1982

Articles with example Lisp (programming language) code
Tennantite. Tennantite is a copper arsenic sulfosalt mineral with an ideal formula . Due to variable substitution of the copper by iron and zinc the formula is . It is gray-black, steel-gray, iron-gray or black in color. A closely related mineral, tetrahedrite ) has antimony substituting for arsenic and the two form a solid solution series. The two have very similar properties and is often difficult to distinguish between tennantite and tetrahedrite. Iron, zinc, and silver substitute up to about 15% for the copper site.

The mineral was first described for an occurrence in Cornwall, England in 1819, where it occurs as small crystals of cubic or dodecahedral form, and was named after the English chemist Smithson Tennant (1761–1815).

It is found in hydrothermal veins and contact metamorphic deposits in association with other Cu–Pb–Zn–Ag sulfides and sulfosalts, pyrite, calcite, dolomite, siderite, barite, fluorite and quartz.

The arsenic component of tennantite causes the metal smelted from the ore to be harder than that of pure copper, because it is a copper-arsenic alloy. In the later 20th century, it was found that arsenical coppers had been more widely used in antiquity than had been previously realised, and it has been proposed that discoveries made by smelting ores like tennantite were significant steps in the progress towards the Bronze Age.

See also

List of minerals
List of minerals named after people

References

Copper ores
Sulfosalt minerals
Cubic minerals
Minerals in space group 217
Blendes
Eccentric (mechanism). In mechanical engineering, an eccentric is a circular disk (eccentric sheave) solidly fixed to a rotating axle with its centre offset from that of the axle (hence the word "eccentric", out of the center).

It is used most often in steam engines, and used to convert rotary motion into linear reciprocating motion to drive a sliding valve or pump ram. To do so, an eccentric usually has a groove at its circumference closely fitted a circular collar (eccentric strap). An attached eccentric rod is suspended in such a way that its other end can impart the required reciprocating motion. A return crank fulfills the same function except that it can only work at the end of an axle or on the outside of a wheel whereas an eccentric can also be fitted to the body of the axle between the wheels. Unlike a cam, which also converts rotary into linear motion at almost any rate of acceleration and deceleration, an eccentric or return crank can only impart an approximation of simple harmonic motion.

On bicycles

The term is also used to refer to the device often used on tandem bicycles with timing chains, single-speed bicycles with a rear disc brake or an internal-geared hub, or any bicycle with vertical dropouts and no derailleur, to allow slight repositioning, fore and aft, of a bottom bracket to properly tension the chain.

They may be held in place by a built-in wedge, set screws threaded into the bottom bracket shell, or pinch bolts that tighten a split bottom bracket shell. As a standard sized bottom bracket threads into the eccentric, an oversized bottom bracket shell is required to accommodate the eccentric.

Gallery

See also

References

Mechanisms (engineering)
Body of water. A body of water or waterbody is any significant accumulation of water on the surface of Earth or another planet. The term most often refers to oceans, seas, and lakes, but it includes smaller pools of water such as ponds, wetlands, or more rarely, puddles. A body of water does not have to be still or contained; rivers, streams, canals, and other geographical features where water moves from one place to another are also considered bodies of water.

Most are naturally occurring geographical features, but some are artificial. There are types that can be either. For example, most reservoirs are created by engineering dams, but some natural lakes are used as reservoirs. Similarly, most harbors are naturally occurring bays, but some harbors have been created through construction.

Bodies of water that are navigable are known as waterways. Some bodies of water collect and move water, such as rivers and streams, and others primarily hold water, such as lakes and oceans.

Bodies of water are affected by gravity, which is what creates the tidal effects. Moreso, the impact of climate change on water is likely to intensify as observed through the rising sea levels, water acidification and flooding. This means that climate change has pressure on water bodies.

Climate change significantly affects bodies of water through rising temperatures, altered precipitation patterns, and sea-level rise. Warmer temperatures lead to the melting of glaciers and polar ice, contributing to rising sea levels and affecting coastal ecosystems. Freshwater bodies, such as rivers and lakes, are experiencing more frequent droughts, affecting water availability for communities and biodiversity. Moreover, ocean acidification, caused by increased carbon dioxide absorption, threatens marine ecosystems like coral reefs. Collaborative global efforts are needed to mitigate these impacts through sustainable water management practices.

Types 

Bodies of water can be categorized into:
 Rain water
 Surface water
 Underground water

There are some geographical features involving water that are not bodies of water, for example, waterfalls, geysers and rapids.

Gallery

See also

 
 
 
 Glossary of landforms

References

Sources 
 Mitsch, W.J. and J.G. Gosselink. 2007. Wetlands, 4th ed., John Wiley & Sons, Inc., New York, 582 pp.

Citations

External links 

 Types of Water Bodies (archived 12 November 2011)
Bell housing. Bellhousing (aka bell-housing or bell) is a colloquial term for the component that aligns and connects the transmission of a vehicle to its engine, and which covers and protects the flywheel/clutch or flexplate/torque converter.  It derives its name from the bell-like shape that those internal components necessitate. The starter motor may mount to it, and it may support clutch and/or shifter linkage.

A Bellhousing may be a separate housing bolted to the gearbox, or it may be an integral portion of the transmission housing, particularly with front wheel drive transmissions. An integral bell has a front bolt pattern that matches the engine to which it will be paired, and a divorced bell additionally has a rear bolt pattern that matches the gearbox to which it will be paired. The use of different bellhousings on a transmission allows the same transmission to be used on multiple engines in multiple applications.

References

See also
 List of auto parts
 List of Chrysler bellhousing patterns
 List of Ford bellhousing patterns
 List of GM bellhousing patterns
 List of Transmission mounting-bolt patterns

Auto parts
SMSQ/E. SMSQ/E is a computer operating system originally developed in France by Tony Tebby, the designer of the original QDOS operating system for the Sinclair QL personal computer. It began life as SMSQ, a QDOS-compatible version of SMS2 intended for the Miracle Systems QXL emulator card for PCs. This was later developed into an extended version, SMSQ/E, for the Atari ST. It consists of a QDOS compatible SMS kernel, a rewritten SuperBASIC interpreter called SBasic, a complete set of SuperBASIC procedures and functions and a set of extended device drivers originally written for the QL emulator for the Atari ST.

It also integrates many extensions previously only available separately for the QL, like Toolkit II (quite essential SuperBASIC add-on), the Pointer Environment (the QL's mouse and windowing system) and the Hotkey System 2.

While SMSQ/E does not run on any unmodified QL, it runs on all of the more advanced QL compatible platforms, from the Miracle Systems (Super)GoldCard CPU plug-in cards to the Q60 motherboard.

History 

In late 1995 a German author, Marcel Kilgus, acquired the SMSQ/E sources for adaptation to his QL emulator QPC, which from then on did not emulate any specific QL hardware anymore but employed specially adapted device drivers to achieve a tighter integration and faster emulation.

In 2000, version 2.94 was the first QL operating system that broke free of the bounds of the QL 8 colour screen, introducing GD2 (Graphic Device Interface Version 2), a QL compatible 16-bit high colour graphics sub-system.

Up to version 2.99 the system was exclusively developed by Tony Tebby and Marcel Kilgus. In 2002, Tebby released all of his source code (which doesn't include most QPC specific parts), albeit under a license which is not open source under the Open Source Definition.
With this step Tony Tebby finally left the QL scene, but development by volunteers continues to this day.

In early 2013 the current source code was re-released under the BSD license.

Currently SMSQ/E consists of approximately 2000 68k assembler source files containing about 222,000 lines of code.

References

External links 

 A Brief History of SMSQ/E
 The official SMSQ/E site Source Code, binaries and documentation
 QPC: a software emulator for DOS/Windows that employs SMSQ/E
 Q40/Q60: a 68040/68060 based motherboard for SMSQ/E
 SMSQmulator - Java based virtual QL machine running SMSQ/E
 QL/E The QL runtime Environment with SMSQ/E
 The Distribution, 4.7 GB of QL related documents, software (incl. all SMSQ/E editions) and pictures

Discontinued operating systems
Atari operating systems
Atari ST software
Software using the BSD license
FLASK. The Flux Advanced Security Kernel (FLASK) is an operating system security architecture that provides flexible support for security policies. It is a joint venture between the National Security Agency, the University of Utah, and the Secure Computing Corporation project designed to provide a framework for a more secure operating system. Development and implementation started with the Mach microkernel, and has since shifted its focus to the Linux operating system. FLASK is a core framework in security-focused operating systems such as NSA's Security-Enhanced Linux (SELinux), OpenSolaris FMAC and TrustedBSD. This means that SELinux can be thought of as an implementation of FLASK.

References

External links
Univ of Utah FLASK site
SELinux from the NSA
TrustedBSD
OpenSolaris Project: Flexible Mandatory Access Control
Flask: Flux Advanced Security Kernel
GFAC: A similar Framework concept implemented in RSBAC

Operating system security
Linux security software
Ammonal. Ammonal is an explosive made up of ammonium nitrate and aluminium powder. TNT is added to create T-ammonal which improves properties such as brisance. The mixture is often referred to as Tannerite, which is a brand of ammonal. 

The ammonium nitrate functions as an oxidizer and the aluminium as fuel. The use of the relatively cheap ammonium nitrate and aluminium makes it a replacement for pure TNT.

The mixture is affected by humidity because ammonium nitrate is highly hygroscopic. Ammonal's ease of detonation depends on fuel and oxidizer ratios, 95:5 ammonium nitrate and aluminium being fairly sensitive, however not very oxygen balanced. Even copper metal traces are known to sensitize bulk amounts of ammonium nitrate and further increase danger of spontaneous detonation during a fire, most likely due to the formation of tetramines. More oxygen balanced mixtures are not easily detonated, requiring a fairly substantial shock, though it remains more sensitive than trinitrotoluene and C-4.

The detonation velocity of ammonal is approximately .

History
From early 1916, the British Army employed ammonal for their mines during World War I, starting with the Hawthorn Ridge mine during the Battle of the Somme, and reaching a zenith in the mines in the Battle of Messines which were exploded on 7 June 1917 at the start of the Third Battle of Ypres (also known as the Battle of Passchendaele). Several of the mines in the Battle of Messines contained 30,000 lbs (over 13.6 tonnes) of ammonal, and others contained 20,000 lbs (over 9 tonnes). The joint explosion of the ammonal mines beneath the German lines at Messines created 19 large craters, killing 10,000 German soldiers in one of the largest non-nuclear explosions in history. Not all of the mines laid by the British Army at Messines were detonated, however. Two mines were not ignited in 1917 because they had been abandoned before the battle, and four were outside the area of the offensive. On 17 July 1955, a lightning strike set off one of these four latter mines. There were no human casualties, but one cow was killed. Another of the unused mines is believed to have been found in a location beneath a farmhouse, but no attempt has been made to remove it.

Ammonal used for military mining purposes was generally contained within metal cans or rubberised bags to prevent moisture ingress problems. The composition of ammonal used at Messines was 65% ammonium nitrate, 17% aluminium, 15% trinitrotoluene (TNT), and 3% charcoal. Ammonal remains in use as an industrial explosive. Typically, it is used for quarrying or mining purposes.

ETA, a Basque separatist organisation, used 250 kg of ammonal in a car bomb in its attack on the Zaragoza barracks on 11 December 1987 in Zaragoza, Spain.

Proportions
A T-ammonal mixture previously used in hand grenades and shells has the proportions (by mass):
 ammonium nitrate 58.6%
 aluminium powder 21%
 charcoal 2.4%
 TNT 18%

See also
 Amatol
 ANFO 
 BLU-82 "Daisy Cutter"
 Tritonal

References

Explosives
RLV. RLV9 can refer to:

 Reusable launch vehicle, the general concept of Reusable launch vehicles (to space) 
 Reusable Launch Vehicle program (NASA), a cancelled NASA program that included the X33 experimental craft
 RLV-TD, India's Reusable Launch Vehicle - Technology Demonstrator project
 Relevium Technologies Inc, Stock Symbol: RLV
 Restrained Life Viewer for Second Life
 Defence of the Reich, the World War II German Reichsluftverteidigung (RLV) defensive aerial campaign 
 RLV College of Music and Fine Arts, Kerala, India
HMS Ace (P414). HMS Ace (P414) was the name allocated to an  of the Royal Navy which was laid down on 3 December 1943 and launched at Devonport Dockyard on 14 March 1945 during the Second World War.

She was not completed because of the end of the war, however the hull was used for explosives testing before arrival in June 1950 to Messrs. Smith & Houston of Port Glasgow, Scotland to be broken up.

References

Amphion-class submarines
1945 ships
Texel (graphics). In computer graphics, a texel, texture element, or texture pixel  is the fundamental unit of a texture map. Textures are represented by arrays of texels representing the texture space, just as other images are represented by arrays of pixels.

Texels can also be described by image regions that are obtained through simple procedures such as thresholding. Voronoi tesselation can be used to define their spatial relationships—divisions are made at the midpoints between the centroids of each texel and the centroids of every surrounding texel for the entire texture. This results in each texel centroid having a Voronoi polygon surrounding it, which consists of all points that are closer to its own texel centroid than any other centroid.

Rendering

When texturing a 3D surface or surfaces (a process known as texture mapping), the renderer maps texels to appropriate pixels in the geometric fragment (typically a triangle) in the output picture.  On modern computers, this operation is accomplished on the graphics processing unit.

The texturing process starts with a location in space.  The location can be in world space, but typically it is local to a model space so that the texture moves with the model.  A projector function is applied to the location to change the location from a three-element vector () to a two-element () vector with values ranging from zero to one (uv). These values are multiplied by the resolution of the texture to obtain the location of the texel.  When a texel is requested that is not on an integer position, texture filtering is applied.

When a texel is requested that is outside of the texture, one of two techniques is used: clamping or wrapping. Clamping limits the texel to the texture size, moving it to the nearest edge if it is more than the texture size. Wrapping moves the texel in increments of the texture's size to bring it back into the texture. Wrapping causes a texture to be repeated; clamping causes it to be in one spot only.

See also
 Pixel
 Resel
 Voxel

References

3D rendering
Texture mapping