omniomni/omni-engineering huggingface dataset:
German submarine U-656. German submarine U-656 was a German Type VIIC U-boat built for the Nazi Germany's Kriegsmarine for service during World War II. She was ordered on 9 October 1939 and the keel laid on 4 September 1940. Construction on U-656 was carried out by Hamburg company Howaldtswerke as yard number 805. She was launched on 8 July 1941 and commissioned on 17 September 1941.

Design
German Type VIIC submarines were preceded by the shorter Type VIIB submarines. U-656 had a displacement of  when at the surface and  while submerged. She had a total length of , a pressure hull length of , a beam of , a height of , and a draught of . The submarine was powered by two Germaniawerft F46 four-stroke, six-cylinder supercharged diesel engines producing a total of  for use while surfaced, two Siemens-Schuckert GU 343/38–8 double-acting electric motors producing a total of  for use while submerged. She had two shafts and two  propellers. The boat was capable of operating at depths of up to .

The submarine had a maximum surface speed of  and a maximum submerged speed of . When submerged, the boat could operate for  at ; when surfaced, she could travel  at . U-656 was fitted with five  torpedo tubes (four fitted at the bow and one at the stern), fourteen torpedoes, one  SK C/35 naval gun, 220 rounds, and a  C/30 anti-aircraft gun. The boat had a complement of between forty-four and sixty.

Service history

U-656 went into service initially with 5th U-boat Flotilla for training from 17 September 1941 until 31 December 1941. She moved into operational service with 1st U-boat Flotilla on 1 January 1942, and was commanded by Kapitänleutnant Ernst Kröning.

U-656 made two patrols, but did not sink any ships. Her first patrol lasted almost two weeks: after departing Kiel on 15 January 1942, she put in at Brest, France on 28 January. The submarine departed Brest on 4 February, but never completed her second patrol. She was sunk with all hands by depth charges dropped by a United States Navy PBO-1 Hudson of Patrol Squadron 82 (VP-82) on 1 March 1942 south of Cape Race, Newfoundland. U-656 became the first U-boat to be sunk by the U.S. Navy in World War II.

References

Bibliography

External links

German Type VIIC submarines
U-boats commissioned in 1941
U-boats sunk in 1942
U-boats sunk by US aircraft
World War II submarines of Germany
World War II shipwrecks in the Atlantic Ocean
Shipwrecks of the Newfoundland and Labrador coast
1941 ships
U-boats sunk by depth charges
Ships built in Hamburg
Submarines lost with all hands
Maritime incidents in March 1942
Hypsometric equation. The hypsometric equation, also known as the thickness equation, relates an atmospheric pressure ratio to the equivalent thickness of an atmospheric layer considering the layer mean of virtual temperature, gravity, and occasionally wind. It is derived from the hydrostatic equation and the ideal gas law.

Formulation
The hypsometric equation is expressed as:

where:
 = thickness of the layer  [m],
 = geometric height [m],
 = specific gas constant for dry air,
 = mean virtual temperature in Kelvin [K],
 = gravitational acceleration [m/s2],
 = pressure [Pa].

In meteorology,  and  are isobaric surfaces. In radiosonde observation, the hypsometric equation can be used to compute the height of a pressure level given the height of a reference pressure level and the mean virtual temperature in between. Then, the newly computed height can be used as a new reference level to compute the height of the next level given the mean virtual temperature in between, and so on.

Derivation 

The hydrostatic equation:

where  is the density [kg/m3], is used to generate the equation for hydrostatic equilibrium, written in differential form:

This is combined with the ideal gas law: 

 

to eliminate :

This is integrated from  to :

R and g are constant with z, so they can be brought outside the integral.
If temperature varies linearly with z (e.g., given a small change in z),
it can also be brought outside the integral when replaced with , the average virtual temperature between  and .

Integration gives

simplifying to

Rearranging:

or, eliminating the natural log:

Correction 
The Eötvös effect can be taken into account as a correction to the hypsometric equation. Physically, using a frame of reference that rotates with Earth, an air mass moving eastward effectively weighs less, which corresponds to an increase in thickness between pressure levels, and vice versa. The corrected hypsometric equation follows:

where the correction due to the Eötvös effect, A, can be expressed as follows:

where
 = Earth rotation rate,
 = latitude,
 = distance from Earth center to the air mass,
 = mean velocity in longitudinal direction (east-west), and
 = mean velocity in latitudinal direction (north-south).

This correction is considerable in tropical large-scale atmospheric motion.

See also
Barometric formula
Vertical pressure variation

References

Equations
Vertical position
Atmospheric pressure
HVC. HVC may refer to:

HVC (avian brain region), an area in the avian brain involved in song production and vocal learning
HVC, the product code used by Nintendo for Famicom hardware and software in Japan
Haitian Vodou Culture Language (ISO 639-3 code)
High-velocity cloud, a common astronomical phenomenon
Himachal Vikas Congress, an Indian political party
Holographic Versatile Card, a piece of computer hardware
Hypervisor call, the interface between virtual machine software and a guest running under it.
High-value chemicals, see high value products
Trondhjems Elektricitetsværk og Sporvei. Trondhjems Elektricitetsværk og Sporvei was a municipally owned power company and tram operator in Trondheim, Norway between 1901 and 1936 when the company was split in Trondheim Energiverk (TEV) and Trondheim Sporvei. The company was founded on November 4, 1901, to build a hydro electric power plant at Øvre Leirfoss and the Trondheim Tramway that replaced the old horse omnibus service from 1893.

Through the company the tramway in Trondheim was expanded to Elgeseter with Elgeseterlinjen in 1913 and to Trondheim Central Station. The company was organised as a municipal agency. Today both the successors of the company are owned by the Government of Norway with TEV being a subsidiary of Statkraft while Trondheim Sporvei now is part of Team Trafikk, a subsidiary of Nettbuss.

References
TEV History

Trondheim Tramway operators
Companies based in Trondheim
Defunct electric power companies of Norway
Companies formerly owned by municipalities of Norway
Defunct railway companies of Norway
Defunct companies of Norway
Railway companies established in 1901
Railway companies disestablished in 1936
1936 disestablishments in Norway
Norwegian companies established in 1901
Sokha. In Russia, Finland, and a few nearby countries, a sokha (; ) is a light wooden ard, consisting of two body ards, with their parallel beams forming the two shafts for a single horse-drawn tillage implement with two socket shares (рассоха). In later types the double body is combined into one wooden board. Chronicles and other literary sources show that the sokha was in use in Russia at least since the 13th century. It originated from northern Russia, e.g., around Novgorod.

The sokha adapts the body ard to a single-animal harness following the pattern of a shaft-drawn cart and adds a spade-like component that turned over the soil. (On ploughs the curved mouldboard both cuts and turns the soil.) Other design features can vary depending on local building custom.

References

Bibliography
 George Vernadsky. A History of Russia. (Yale University Press, 1969) ().

See also

 Timeline of Russian inventions and technology records

Agricultural machinery
Animal equipment
Gardening tools
Science and technology in Russia
Russian inventions
Ploughs

nn:Ard
Gaar, Scott & Co.. Gaar, Scott & Co., was an American threshing machine and steam traction engine builder founded in 1849 and based in  Richmond, Indiana. The company built simple and compound engines in sizes from 10 to 50 horsepower. Farm machinery produced by the firm were advertised as part of "the Tiger Line" and used a tiger upon two globes as the company logo.  In the Fall of 1869, A. Gaar & Co. won "Best Portable Farm Steam Engine" and "Best Eight Horse Power" at the 17th Illinois State Fair, for which it won two Silver Medal prizes.  It merged with the M. Rumley Co. in 1911 during a purchasing frenzy that put the later firm into insolvency.  The company was reorganized as Advance-Rumely Thresher Company Inc.  Advance-Rumely Thresher Company was later purchased by Allis-Chalmers Mfg. Co.

The Abram Gaar House and Farm is listed on the National Register of Historic Places and open as a historic house museum.  The Gaar-Scott office building, designed by noted architect John A. Hasecoster, still stands in Richmond and is the headquarters of Richmond Baking, a large commercial baker.

References

External links
Restoration of one of the two remaining 40hp Gaar-Scott traction engines

Agricultural machinery manufacturers of the United States
Richmond, Indiana
Defunct companies based in Indiana
Steam engine manufacturers
1849 establishments in Indiana
1911 disestablishments in Indiana
Manufacturing companies established in 1849
Manufacturing companies disestablished in 1911
Allis-Chalmers Manufacturing Company
Koolhoven F.K.52. Koolhoven F.K.52 was a Dutch-designed, two-seat reconnaissance-fighter biplane, which was developed in the 1930s by Koolhoven. The aircraft was equipped with an enclosed cockpit and single-strut landing gear. Only six aircraft were produced. The aircraft saw some service in the Finnish Air Force.

Design and development
The FK.52 was proposed as a replacement for the Fokker C.Vs of the Luchtvaartafdeling (LVA), the Dutch Army Air Force. The prototype aircraft made its maiden flight on February 9, 1937. The aircraft was however lost in an accident on August 11 of the same year, while displaying in front of Boy Scouts during the 5th World Scout Jamboree.

Although the Koolhoven was an obsolete design by 1938, they began building a few FK.52s. The Dutch Air Force ordered 36 aircraft in 1939, but only five had been manufactured, when the Germans invaded the Netherlands.

Operational history
During the Winter War, two Koolhovens were purchased by the Swedish count Carl Gustav von Rosen and given to the Finnish Air Force. The aircraft was flown to Finland on January 18, 1940 with the codes KO-129 and KO-130. In March 1940 they bombed and strafed Soviet troops attacking over ice towards Virolahti. During the Winter War, they summed up about 15 combat sorties. Both FK.52 planes were hit by enemy fire.

In 1941 the aircraft were used by LeLv 6 in the Hanko area. Both aircraft were destroyed during the Continuation War, KO-130 became lost during a leaflet-dropping mission over Hanko and made a forced-landing 80 km south of Tallinn, Estonia on August 16, 1941. Both crew members died in the crash. Estonian Forest brothers guerrillas burned the plane and buried the crew in Velise.

The other aircraft, KO-129, was destroyed in an accident in 1943. The pilot bailed out and survived. The plane crashed north of the village Pernaa in Kauhava.

The nickname of the plane was Kolho, "clumsy"

Operators

Finnish Air Force operated two aircraft.

Royal Netherlands Air Force

Specifications (F.K.52)

See also

References

1930s Dutch military reconnaissance aircraft
Biplanes
Single-engined tractor aircraft
FK52
Aircraft first flown in 1937
NVI F.K.31. NVI F.K.31 was a Dutch designed parasol wing two seat reconnaissance-fighter, which was developed in the 1920s by Frederick Koolhoven.  The aircraft saw some service in the Finnish Air Force.

History

The F.K.31 became Koolhoven's first design for the N.V. Nationale Vliegtuig Industrie ("National Aircraft Industry") a two-seat scout and fighter. Its prototype became the sensation of the Paris Air Salon of 1922. However, the production of the F.K.31 met with many difficulties, forcing the N.V. Nationale Vliegtuig Industrie to close down.

Further development was carried out in France, resulting in the De Monge M.101 C2, but only a single example was built, powered by a Gnome & Rhône 9Ac radial engine.

Use in Finland
The Finnish Air Force used twelve F.K.31s between 1926-1932. The aircraft had been purchased while the development still was being carried out. The Finnish pilots disliked the aircraft and the Finnish Air Force F.K.31s flew for fewer than 6 hours each.

The Koolhoven F.K.31 was called Kolho ("Clumsy") or Kolhovene ("Clumsy Boat") in the Finnish Air Force.

Operators
  
 Finnish Air Force
 
 LA-KNIL

Specifications

References

 

F.K.31
1920s Dutch military reconnaissance aircraft
Parasol-wing aircraft
Single-engined tractor aircraft
Aircraft first flown in 1923
Aircraft of the Royal Netherlands East Indies Army
Ziegelei Lage. The Ziegelei Lage was a brickyard in Lage, North Rhine-Westphalia, Germany, that was founded in 1909 and closed in 1979.

The initial production of the bricks was done without any machines. The first machines were installed in 1922, after which more machines were gradually added.

Today, the brickyard is a historical museum that demonstrates the production of bricks. The machines are turned on twice a year, and used to form about 10,000 bricks each time. This "festival", where visitors can observe and make bricks themselves, is called "Gut Brand".  The bricks are cured by the traditional method in the Hoffmann'schen circular kiln.

The museum also includes a small house that visitors can enter, that demonstrates how families lived in the time that the brickyard was open. The house includes articles such as a Pickert on a wall and old tools.

The Ziegelei Lage is the central point for the European Route of Industrial Heritage.

References 

Industry museums in Germany
Museums in North Rhine-Westphalia
Ecology Flag. The Ecology Flag is a cultural symbol used primarily in the 1970s by American environmentalists. It is a symbol of people's commitment to clean up the environment.

Description 
Ron Cobb created an ecology symbol which he published on October 25, 1969 in the Los Angeles Free Press and then placed in the public domain.  The symbol was formed by taking the letters "e" and "o", taken from the words "environment"  and "organism", and putting them in superposition, thereby forming a shape reminiscent of the Greek letter Θ (Theta). 

Jack Shepherd, then Senior Editor at Look magazine, incorporated Cobb’s symbol into an image of a flag for Look’s April 21, 1970 issue. This widely popularized the theta symbol, which is associated with the Greek word thanatos (death), pointing to human threats to the environment and atmosphere of the earth. Shepherd patterned the flag after the flag of the United States, with thirteen stripes alternating green and white, the green standing for unspoiled land and the white for clean air. Its canton was green with the ecology symbol where the stars would be in the United States flag.

History 

The Ecology Flag was designed in 1970 by Jack Shepherd, then Senior Editor at Look Magazine, to promote the first Earth Day. Shepherd and colleagues Christopher Wren, and David Maxie, hung the first Ecology flag from the 5th floor window of the Look Building on Madison Avenue at 51st,  next door to St Patrick’s Cathedral. It went to Washington, D.C. the next day for the first Earth Day March. 

Ecology flags showed up many places in the 1970s. One of the earliest recorded flyings of an actual Ecology Flag was in 1970. As a 16-year-old high school student, Betsy Boze, an environmental advocate and social activist, made a  green and white "theta" ecology flag to commemorate the first Earth Day (then called Ecology Day). Initially denied permission to fly the flag at C. E. Byrd High School in Shreveport, Louisiana, Vogel sought and received authorization from the Louisiana Legislature and Louisiana Governor John McKeithen in time to display the flag for Earth Day. 

As part of an Earth Week celebration in 1970, students at Aiken High School in Aiken, SC received permission to replace the South Carolina state flag on the flagpole outside the school with a home-made Ecology flag. The Ecology Flag flew for a week beneath the American Flag, as documented in the Aiken Standard newspaper of April 21, 1970.

Students at Harper College in Palatine, Illinois made an agreement with the administration to fly a homemade Ecology flag under the U.S. flag for the 1971–1972 school year. The flag flew over the Naval Civil Engineering Laboratory in Port Hueneme, California in 1973 and decorated a building as a mural in Mississippi Palisades State Park in Illinois in 1976.

The flag continues to be used as a symbol of concern for the planet, showing up at the People's Climate March in 2017.

See also 
 Esperanto jubilee symbol
 Earth Flag

References

External links 
 
 The Connection between the Ecology flag and Star Wars at YouTube

Environment of the United States
Activism flags
Ecology
EFW. EFW may refer to:
 Economic Freedom of the World
 Energy-from-waste, see Waste-to-energy
 Jefferson Municipal Airport, in Jefferson, Iowa, IATA airport code EFW
 Electric Field and Wave experiment, a scientific instrument on the Cluster space mission
 Elbe Flugzeugwerke, a Dresden-based subsidiary of Airbus and ST Aerospace specialising in freighter and tanker conversion
Conference room pilot. Conference room pilot (CRP) is a type of software procurement and software acceptance testing. A CRP may be used during the selection and implementation of a software application in an organization or company.

The purpose of the conference room pilot is to validate a software application against the business processes of end-users of the software, by allowing end-users to use the software to carry out typical or key business processes using the new software.  A commercial advantage of a conference room pilot is that it may allow the customer to prove that the new software will do the job (meets business requirements and expectations) before committing to buying the software, thus avoiding buying an inappropriate application.  The term is most commonly used in the context of 'out of the box' (OOTB) or 'commercial off-the-shelf' software (COTS).

Compared to user acceptance testing 
Although a conference room pilot shares some features of user acceptance testing (UAT), it should not be considered a testing process – it validates that a design or solution is fit for purpose at a higher level than functional testing.

Shared features of CRP and UAT include:
End-to-end business processes are used as a "business input" for both
Functionality demonstrations
Non-functional validation(e.g. performance testing)

Differences between a conference room pilot and a formal UAT:
It is attempting to identify how well the application meets business needs, and identify gaps, whilst still in the design phase of the project
There is an expectation that changes will be required before acceptance of the solution
The software is ‘on trial’ and may be rejected completely in favour of another solution.

References

General
https://web.archive.org/web/20120306082951/http://www.ensync-corp.com/consulting/conference_room_pilot.cfm?section=consulting
https://web.archive.org/web/20100410184030/http://www-archive.ui-integrate.uillinois.edu/news_art_crp.asp
https://web.archive.org/web/20120306082951/http://www.bourkeconsulting.com/documents/POCCRPBCAWebsite020903.pdf
https://web.archive.org/web/20120101095056/http://www.smthacker.co.uk/conference_room_pilot.htm

Software testing
Desoutter Aircraft Company. The Desoutter Aircraft Company was a British aircraft manufacturer based in Croydon. It was founded by Marcel Desoutter and produced aircraft during the late 1920s and the 1930s.

History
The company was formed in December 1928 to manufacture the designs of the Dutch Koolhoven company in particular the Koolhoven F.K.41, which had drawn a lot of attention due to its modern design. The licence was obtained and Desoutter set up a production unit at the former ADC factory at Croydon Aerodrome. The F.K.41 became quite successful and was marketed under the name Dolphin. The name "Dolphin" was later dropped and for a while the aircraft was marketed only under the name "Desoutter". A slightly modified version was later produced and the versions received the suffixes Mk.I and Mk.II.

Desoutter's aircraft became a familiar sight in British flying clubs, where they were used for instruction, pleasure flights and taxi flights.

The business folded in 1932 after its main customer, National Flying Services at London Air Park, Hanworth, went into liquidation, having produced 41 aircraft (twenty-eight Mk.Is and thirteen Mk.IIs).

Aircraft
Desoutter Mk.I previously also known as "Dolphin" or simply only as "Desoutter"
Desoutter Mk.II Sports Coupé

See also
List of aircraft manufacturers

References

External links

 Koolhoven Aeroplanes Foundation

1928 establishments in England
1932 disestablishments in England
British companies established in 1928
Defunct aircraft manufacturers of the United Kingdom
Manufacturing companies disestablished in 1932
Manufacturing companies established in 1928
Lightstreamer. Lightstreamer is a web-based asynchronous messaging project, implementing the WebSocket protocol, the Comet model, the push technology paradigm, and the real-time web practices.

Origin
The first version of Lightstreamer was created at the end of 2000, as one of the first attempts to implement real-time data push to HTML pages without employing Java applets. The application domain driving most of the interest in push technology at that time was market data distribution for the financial services industry. In the following years, Lightstreamer was used within other application domains too, including aerospace telemetry, where NASA chose Lightstreamer to push live telemetry data for the International Space Station.

Architecture
The Lightstreamer Server is a high-performance engine that manages all the connections with the clients through the Internet. It integrates with the backend systems via custom adapters. The Data Adapter receives the real-time data flow from the data feed and injects it into the Lightstreamer Server. The Metadata Adapter has control over authentication, authorization, and quality of service.

Lightstreamer Server is made up of three logical layers:

 Web Transport. Lightstreamer implements a bi-directional transport based on standard Web protocols. This means it uses several underlying techniques (WebSocket, Comet, HTTP streaming, etc.) to provide the upper layers with a channel over which data can be exchanged in real-time with any client connected through the Web, even if protected by firewalls and proxies.
 Messaging. Lightstreamer implements a publish–subscribe pattern, suitable for both one-to-many fan-out scenarios and one-to-one messaging needs. It takes care of routing each message to the right recipients, multiplexing the flow of events on the top of each connection with the clients.
 Semantics+QoS+Security. It implements data semantics (tables, schema, metadata, conflation, etc.), network optimization (dynamic throttling, bandwidth control, resampling, batching, etc.), and full session management (authentication, fine-grained authorization, etc.) on the top of publish-subscribe.

Server-side APIs
 Java In-Process Adapter API
 Java Remote Adapter API
 .NET Standard Adapter API
 Node.js Adapter API
 Python Adapter API
 Generic Adapter API (based on TCP sockets)
 JMX Management API

Client-side APIs
 Web Client API
 Node.js Client API
 Android Client API
 Java SE Client API
 .NET Standard Client API
 C++ Client API
 Swift Client API
 iOS Client API
 macOS Client API
 tvOS Client API
 watchOS Client API
 visionOS Client API
 Python Client API
 Flutter Client API
 Flash Client API
 Flex and AIR Client API
 Silverlight Client API
 BlackBerry Client API
 Java ME Client API
 Generic Client API (via a documented protocol)

References

External links
 Lightstreamer web site
 Online Lightstreamer demos
 Lighstreamer named "Cool Vendor" by Gartner

Message-oriented middleware
Push technology