omniomni/omni-engineering huggingface dataset:
Chrome alum. Chrome alum or Chromium(III) potassium sulfate is the potassium double sulfate of chromium. Its chemical formula is KCr(SO4)2 and it is commonly found in its dodecahydrate form as KCr(SO4)2·12(H2O).  It is used in leather tanning.

Production and properties

Chromium alum is produced from chromate salts or from ferrochromium alloys.  Concentrated aqueous solutions of potassium dichromate can be reduced, usually with sulfur dioxide but also with alcohols or formaldehyde, in the presence of sulfuric acid at temperatures <40 °C.  Alternatively and less commonly, ferrochromium alloys can be dissolved in sulfuric acid and, after precipitation of the ferrous sulfate, the chrome alum crystallizes upon addition of potassium sulfate. Chromium alum crystallizes in regular octahedra with flattened corners and is very soluble in water. The solution reddens litmus and is an astringent. Aqueous solutions are dark violet and turns green when it is heated above 50 °C.  In addition to the dodecahydrate, the hexahydrate KCr(SO4)2·6H2O, dihydrate KCr(SO4)2·2H2O, and the monohydrate KCr(SO4)2·H2O are known.

Uses
Chromium alum is used in the tanning of leather as chromium(III) stabilizes the leather by cross linking the collagen fibers within the leather. However, this application is obsolete because the simpler chromium(III) sulfate is preferred.

It was also used in gelatine emulsions in photographic film as hardener.

References

Sulfates
Potassium compounds
Chromium(III) compounds
Coordination complexes
Double salts
Grahame-White Ganymede. The Grahame-White Ganymede was a prototype British heavy night bomber intended to serve with the Royal Air Force in the First World War.  A large, three-engined, twin-boom biplane, the sole prototype Ganymede did not fly until after the war had ended, and although an attempt was made to convert the aircraft to an airliner, it was unsuccessful.

Development and design
In 1918, the Grahame-White Aviation Company of Hendon, London developed a large, long-range heavy bomber intended to equip the Royal Air Force.  The resulting design, the E.IV Ganymede, was of unusual layout, being a three-engined, twin-boom biplane with four-bay wings. Two of the engines were located at the front of the booms, driving tractor propellers, while the third engine was installed at the rear of the central nacelle, driving a pusher propeller.  A biplane tail unit with three fins and rudders spanned the gap between the two main fuselage booms.  The two pilots and a bomb-aimer/gunner were accommodated in the central nacelle, while additional gunners cockpits were provided in each of the fuselage booms, with Scarff ring mountings for a machine gun together with a tunnel opening under the fuselages to allow the gunners to repel attacks from below.

It was intended that the Ganymede be powered by three 400 hp (298 kW) Liberty engine, but concerns about the availability of the American-built Liberty resulted in considerably less powerful Sunbeam Maori engines being specified when an order was placed for three prototypes.  The first of these prototypes, serial number C3481 was completed late in 1918. While it was tested by the Air Ministry during 1919, the RAF had little interest in purchasing a new heavy bomber, and the remaining two prototypes were cancelled.

After being damaged in a landing accident in 1919, Grahame-White rebuilt the Ganymede into a civil airliner, becoming the E.9 Ganymede.  The central engine was removed completely, while the two remaining engines were replaced by 450 hp (336 kW) Napier Lions.  The nacelle was rebuilt with two pilots in an open cockpit ahead of a glazed cabin housing 12 passengers.  The modified aircraft was granted a Certificate of Airworthiness on 12 September 1919, with the Aircraft registration G-EAMW, but was destroyed in a fire in September 1920.

Specifications (Bomber)

See also

Notes

References

"The Grahame-White Day Bomber "Ganymede"" . Flight, 10 April 1919, p. 472.
Bruce, J.M. British Aeroplanes 1914-18. London:Putnam, 1957.
Jackson, A.J. British Civil Aircraft since 1919: Volume 2. London:Putnam, Second edition, 1973. .
Mason, Francis K. The British Bomber since 1914. London:Putnam, 1994. .
 .

1910s British bomber aircraft
Ganymede
Three-engined push-pull aircraft
Twin-boom aircraft
Biplanes
Aircraft first flown in 1919
Aircraft with fixed conventional landing gear
Triple-tail aircraft
Three-engined piston aircraft
Mekanika Uru. The Uru is a submachine gun made by the production firm Mekanika in 1977 for the Brazilian Army and Police Forces. License for weapons in 1988, bought the branch of FAU, which modernized the Thompson submachine gun in model 2. SACO Defense of the US manufactured the Uru as the Model 683 for countries without an industrial basis but were sued for copyright violations.

The overall weapon has a cylindrical body. It made the front of the air vents for cooling trunk. A tubular casing in a shop, serving also as the front handle, trigger and pistol grip. There is also a safety/selector switch, which can be translated into two points: first - for self-shooting, second - for the automatic.

There are a few different versions of the Uru: standard models chambered in 9mm Parabellum, which include early models with fixed tubular stocks and later examples with both wire and tubular folding stocks, and a pistol-caliber carbine in .38 ACP with a wooden buttstock. Optional accessories include a conical flash hider and a special barrel featuring an integrated sound suppressor that the operator may swap to rather than the standard barrel pattern.

References

External links
 https://www.youtube.com/watch?v=D_dXVwZb33Q (Dissasembly and internal mechanics)
 Описание пистолета-пулемёта «Уру 2» на www.fire-arms.ru
 http://www.janes.com/articles/Janes-Infantry-Weapons/Uru-9-mm-sub-machine-guns-Brazil.html
 https://web.archive.org/web/20100106232455/http://www.probertencyclopaedia.com/cgi-bin/res.pl?keyword=Uru&offset=0
 http://www.securityarms.com/20010315/galleryfiles/1900/1908.htm
 http://www.securityarms.com/20010315/galleryfiles/2800/2872.htm

9mm Parabellum submachine guns
Submachine guns of Brazil
Technology-enhanced active learning. Technology-enhanced active learning, or TEAL, is an alternative  method of teaching that MIT pioneered. Led by Professor John Belcher, the TEAL approach showed that it was possible to challenge the passive or recitation style of teaching, common in large classes and re-enforced by lecture halls architecture. Despite having excellent math results, many first-year students had not transitioned across to the way lecturers teach and 40% of students dropped out of first year physics education at MIT. The TEAL approach set out to assist students to "visualize, develop better intuition about, and conceptual models" of scientific concepts.

A situated model for teaching with technology 
The TEAL approach, alternately referred to as Studio Physics, eschewed the traditional university lecture, which encouraged passivity. Using a collaborative active learning approach, students would sit in groups of nine around 13 tables, where they were expected to complete problem-solving activities, refer to laptop computers and then project their own solutions on a screen and compare the results with their peers.

History behind TEAL
The TEAL alternative was based on a pedagogical model that was instituted at Rensselaer Polytechnic Institute by Jack Wilson in 1994. Since the TEAL approach had a robust assessment component, the implementors were able to understand the students perspective on the learning environment. Class attendance was a key component of the course, and students had to see this as a profitable use of their time.

Current Use and Future Directions
In 2014 TEAL+x, emerged, a combination between the TEAL format with MITx. The TEAL approach is currently in use at the Rensselaer Polytechnic Institute, North Carolina State University, University of Colorado, Harvard University, and the University of Maryland. The biggest lesson from this model is that robust assessment effort need to accompany educational innovations right from the start, and that all academics need to be inducted into the methodology.

See also
Active learning
CDIO Initiative
SCALE-UP

References

Teaching
Massachusetts Institute of Technology
Andreas Wilhelm Schwarzlose. Andreas Wilhelm Schwarzlose (31 July 1867 – 1936) was a German ( Prussian) firearm designer who is best known for designing a blowback-operated machine gun.

Early life
Schwarzlose was born near Wust, and served as an artilleryman and armorer in the Austro-Hungarian army. He graduated from the National Ordnance College and designed his first pistol in 1892, although it never saw production. In the 1890s, he lived and worked in Suhl and designed the machine gun, he later got famous for. The MG was produced - mainly for the Austrian air forces - by the Österreichische Waffenfabriks-Gesellschaft. In 1897, he opened an arms factory in Berlin which he operated until 1919 when it was shut down by the Allied Disarmament Commission.

After the closing of his factory he worked as a firearms consultant until his death in 1936.

Designs
Schwarzlose MG M.07/12 machine gun (for Austria-Hungary)
Schwarzlose Model 1898 semi-automatic pistol
Schwarzlose Model 1908 semi-automatic pistol

References

Firearm designers
1936 deaths
1867 births
People from Charlottenburg
Expatriates in Austria-Hungary
German expatriates
Specialist (short story). "Specialist" is a science fiction short story by American writer Robert Sheckley. It was first published in 1953 and has appeared in various collections, including Untouched by Human Hands (1954) and The Golden Age of Science Fiction, edited by Kingsley Amis in 1981.

Plot

A galactic deep-space cargo bioship is blown off course by a photon storm. When the crew recover, they find themselves in an unexplored region of space and their only member of the Pusher race, which allows the ship to travel faster than light, is dead.

The Crew comprises varied members of vastly different intelligent races, all in close mental rapport known as the Cooperation, and serving specialized functions; they are known as Engine, Thinker, Eye etc. But without a Pusher, they cannot sustain FTL speeds and are unlikely to reach home before most of the crew die of old age. They manage to locate a planet rich in primitive Pushers, Earth. The crew try to communicate with a man they find, but he is so violent and resistant that they are forced to bring him on board the ship to try to reason with him.  The Crew, used to close cooperation, find it hard to understand his mistrust and fear.

Gradually, the man begins to realize the nature of the Crew and the pleasure to be found as a part of the Cooperation. He agrees to join the crew. Hesitantly at first, he tries to push and finally learns how it is done. The ship speeds away.

External links
 
"Specialist" at the Internet Archive

Science fiction short stories
Short stories by Robert Sheckley
Don Bosco School. Don Bosco School may refer to:

India

 Don Bosco College, Maram
 Don Bosco School, Bagnan
 Assam Don Bosco University
 Don Bosco College, Tura
 Don Bosco Academy, Patna 
 Don Bosco School, Darbhanga 
 Don Bosco Bandel, West Bengal
 Don Bosco College of Engineering, in Goa
 Don Bosco High & Technical School, Liluah, Howrah, West Bengal
 Don Bosco High School (Imphal)
 Don Bosco High School, Matunga, Mumbai
 Don Bosco High School, Borivali (W), Borivali, Mumbai
 Don Bosco High School, Nashik
 Don Bosco High School, Baghchung
 Don Bosco High School, Guwahati
 Don Bosco High School, Hojai
 Don Bosco Higher Secondary School, Irinjalakuda, Kerala
 Don Bosco Institute of Technology, Bangalore
 Don Bosco Institute of Technology, Mumbai
 Don Bosco Matriculation Higher Secondary School, Chennai, Egmore, Chennai
 Don Bosco School (Alaknanda, New Delhi)
 Don Bosco School, Park Circus, Kolkata
 St. Don Bosco's College, Lakhimpur Kheri
Don bosco school Berhampore
Don bosco school Siliguri
Don bosco school Don Bosco Bandel
Don bosco school Kharagpur

Pakistan

 Don Bosco Catholic School, Bannu

The Philippines

 Caritas Don Bosco School, Biñan
 Don Bosco College, Canlubang
 Don Bosco Technical College, Mandaluyong
 Don Bosco Technical College–Cebu
 Don Bosco Technical Institute, Makati
 Don Bosco Technical Institute, Tarlac
 Don Bosco Technical Institute, Victorias
 Don Bosco Academy, Pampanga
 Don Bosco School, Manila

United States 

 Don Bosco Technical Institute, Rosemead, California
 Don Bosco Cristo Rey High School, Takoma Park, Maryland
 Don Bosco High School, now part of Saint Thomas More High School, Saint Francis, Wisconsin
 Don Bosco Preparatory High School, Ramsey, New Jersey
 Don Bosco Technical High School (Boston), Massachusetts
 Don Bosco Technical High School (New Jersey), Paterson, New Jersey (closed 2002)
 Don Bosco High School (Iowa)
 St. John Bosco High School, Bellflower, California

Other countries

 Don Bosco Cambodia
 Don Bosco Catholic Secondary School, Ontario, Canada

See also
 Don Bosco Institute of Technology (disambiguation)
List of Salesian schools
 St John Bosco College (disambiguation)
Almaz Shipbuilding Company. The Almaz Shipbuilding Company () is a Russian manufacturing enterprise, specializing in military and commercial ship design, along with its development and production.

Headquartered in St. Petersburg, the factory has 165,000 square metres located in the central part of St. Petersburg on Petrovsky Island (near the Gulf of Finland). It was founded in 1901 for the production of motorboats. It has produced more than a thousand military and commercial ships.

Production 
 Hovercraft
 Patrol boats
 High-speed motor boats

See also
 Lebed-class LCAC
 Aist-class LCAC

References

External links
 Official site of Almaz (www.almaz.spb.ru)
 Almaz Docks
 Almaz Shipbuilding Company at Rusnavy.com

Shipbuilding companies of Russia
Shipbuilding companies of the Soviet Union
Manufacturing companies based in Saint Petersburg
Vehicle manufacturing companies established in 1901
1901 establishments in the Russian Empire
Russian brands
Flammability diagram. Flammability diagrams show the control of flammability in mixtures of fuel, oxygen and an inert gas, typically nitrogen.  Mixtures of the three gasses are usually depicted in a triangular diagram, known as a ternary plot.  Such diagrams are available in the speciality literature.  The same information can be depicted in a normal orthogonal diagram, showing only two substances, implicitly using the feature that the sum of all three components is 100 percent.  The diagrams below only concerns one fuel; the diagrams can be generalized to mixtures of fuels.

Understanding flammability diagrams
Triangular diagrams are not commonplace.  The easiest way to understand them is to briefly go through three basic steps in their construction.  
Consider the first triangular diagram below, which shows all possible mixtures of methane, oxygen and nitrogen.  Air is a mixture of about 21 volume percent oxygen, and 79 volume percent inerts (nitrogen). Any mixture of methane and air will therefore lie on the straight line between pure methane and pure air – this is shown as the blue air-line.  The upper and lower flammability limits of methane in air are located on this line, as shown (labelled UEL and LEL, respectively).
The stoichiometric combustion of methane is: CH4 + 2O2 → CO2 + 2H2O.  The stoichiometric concentration of methane in oxygen is therefore 1/(1+2), which is 33 percent.  Any stoichiometric mixture of methane and oxygen will lie on the straight line between pure nitrogen (and zero percent methane) and 33 percent methane (and 67 percent oxygen) – this is shown as the red stoichiometric line.  The upper and lower flammability limits of methane in oxygen are located on the methane axis, as shown.
The actual envelope defining the flammability zone can only be determined based on experiments.  The envelope will pass through the upper and lower flammability limits of methane in oxygen and in air, as shown.  The nose of the envelope defines the limiting oxygen concentration (LOC)).

See also
 Ternary plot
 Flammability limit

Sources
  (His main work, 6.3Mb download)

References

Safety engineering
Process safety
Fire protection
Combustion
Étang de Soulcem. Étang de Soulcem is a large artificial lake in the Pyrenees mountains in Ariège, France. It is at an elevation of 1570 m and is used for hydroelectricity, generating 62 GWh/year. The lake, which has a surface area of 0.91 km2, was formed following the construction by Électricité de France of a dam across the northern end of the Vicdessos valley in 1980–1983.

The lake contains various fish including brown trout (S. trutta), Arctic char (S. alpinus), brook trout (S. fontinalis), and common minnow (P. phoxinus).

External links

Soulcem
Hydroelectric power stations in France
Dams completed in 1983
Controllable slope soaring. Controllable-slope soaring (also known as Walkalong gliding) is a type of slope soaring where a slope is made to follow a walkalong glider (a lightweight toy aircraft), both sustaining and controlling the glider's trajectory by modifying the wind in the vicinity of the airplane.

A controllable slope is any object which can be used to affect the air under the airplane: a piece of cardboard, the pilot's hands or even head. The controllable slope is usually manipulated by a person following the glider in flight (please see photo at right).

Controllable-slope soaring allows a glider to achieve sustained flight without the need for an onboard aircraft engine or onboard flight control system.

See also 
 Gliding flight
 History of human-powered aircraft
 Orographic lift
 Ridge lift
 Soaring
 Walkalong glider

External links
 Method of Flying Toy Airplane and Means Therefor - a patent from the 1950s for a walkalong glider using controllable slope soaring.

 Principles of flying walkalong gliders using controllable slope soaring (Jersey Shores Middle School students)
 Controllable slope soaring: suitable aircraft and videos (Google sites)

Aircraft controls
Gliding technology
George Turnbull. George Turnbull may refer to:

 George Turnbull (theologian) (1698–1748), Scottish theologian
 George Turnbull (soldier) (1729–1810), Scotland-born loyalist soldier in the American Revolutionary War
 George Turnbull (engineer) (1809–1889), civil engineer active in the UK and India
 George Stanley Turnbull (1882–1977), journalist, historian, and founder of the University of Oregon School of Journalism
 George Turnbull (businessman) (1926–1992), British car manufacturer, associated with British Leyland and Hyundai
 George Turnbull (footballer, born 1911) (1911–1996), English football forward, active 1930s
 George Turnbull (footballer, born 1927) (1927–2002), English football goalkeeper, active 1950s
 George Turnbull (rugby union) (1877–1970), Scottish rugby union player
 George Turnbull of Abbey St Bathans (1793–1855), Scottish lawyer, landowner and agricultural improver
Blackburn Second Monoplane. The Blackburn Second Monoplane was strongly influenced by the French Antoinette and was much more successful than Robert Blackburn's first aircraft. The lone aircraft was built in Leeds, UK in 1910.

Development
The First Monoplane was not a success, barely leaving the ground before crashing. His second machine, the Second Monoplane was very different, and resembled Léon Levavasseur's Antoinette design which Blackburn had seen in France.

The monoplane wing was rectangular with a constant chord, significant dihedral and square tips, and had a thin aerofoil section cambered on the underside, as was usual at the time. Lateral control was by wing warping. The wing was wire braced via a kingpost passing  through the fuselage, extending both above and below. The fuselage was, like the wings, a wooden structure covered with fabric, triangular in section and tapering towards the tail. This was characteristically Antoinette with a long, finely tapering fin and tailplane, the rudder being divided into two triangular sections above and below the elevator, giving it clearance to move.

The pilot's seat was at the trailing edge of the wing, and contained Blackburn's "triple steering column" which was moved up and down for elevator control, from side to side to warp the wings and rotated to move the rudders. This system had been used on the First Monoplane. The undercarriage main axle was carried at the bottom end of the kingpost with wheels at either end and bearing ash fore and aft skids. During development and taxying trials, this structure was braced and sprung in different ways before the undercarriage was deemed satisfactory.

Flying was delayed by the choice of a new untried engine, a seven-cylinder radial designed by R.J.Issacson of the Hunslet Engine Co. of Leeds. This drove a wooden two-blade propeller via a 2:1 reduction gear.

The aircraft was taken to Filey on the English east coast for testing on the sands with B.C.Hucks at the controls. On 8 March 1911, after taxying for several miles, he made the first takeoff. He flew successfully for a while at about 30 ft (10 m) and 50 mph (80 km/h), but he sideslipped into the sands when attempting his first turn.

Despite this mishap, after repair the Second Monoplane did good service at Filey as an instructional aircraft, bringing publicity to Blackburn's name and later machines.

Specifications

References

1910s British experimental aircraft
Second Monoplane
Aircraft first flown in 1911
High-wing aircraft
Single-engined tractor aircraft
Single-engined piston aircraft
Aircraft with fixed conventional landing gear