omniomni/omni-engineering huggingface dataset:
Ariel 3 (moped). The Ariel 3 was a tricycle moped produced by the BSA factory in the UK. The Ariel 3 was a sales flop whose £2M development cost  contributed significantly to the demise of BSA.

Even the Ariel 3's promotion was ill-conceived, the sales slogan being "Here it is - whatever it is!". Cohn Atkinson attributes its failure to a remote management at BSA who "didn't even like bikes" and who "made the most appalling decisions" on production and marketing.

Design
The engine was a Dutch Anker  2-stroke, situated between the rear wheels. The pressed-steel forward section of the frame, supported by torsion bars, could swivel to enable the rider to lean the vehicle into bends like a motorcycle. The front "fork" was a single-sided down tube with a rudimentary rubber block suspension. All three pressed steel wheels were interchangeable. Drive was to just one of the rear wheels, and only one of the rear wheels had a brake, a small drum item. There was a similar front drum brake. A true moped, the Ariel 3's engine was started by first pedalling and then releasing a decompressor trigger. The rider could assist the little motor on hills by pedalling. The six volt headlight was single beam, with no dip. There was no rear suspension.

See also
List of Ariel motorcycles

References

Mopeds
Ariel motorcycles
Motorcycles introduced in 1970
Two-stroke motorcycles
Kenya National Highways Authority. The Kenya National Highways Authority (KeNHA) is an autonomous road agency. Its responsibility is for the management, development, rehabilitation, and maintenance of Class S, A and B roads as explained below.

Location
The headquarters of KeNHA are located at Barabara Plaza, off Mombasa Road, opposite Kenya Civil Aviation Authority HQ in the neighborhood of JKIA, in Nairobi, Kenya's capital and largest city.

Overview
The Government of Kenya divides the roads into several classes, including the following:

 Class S: "A Highway that connects two or more cities and carries safely a large volume of traffic at the highest speed of operation".  
 Class A: "A Highway that forms a strategic route and corridor connecting international boundaries at identified immigration entry and exit points and international terminals such as international air or sea ports".
 Class B: "A Highway that forms an important national route linking national trading or economic hubs, County Headquarters and other nationally important centers to each other and to the National Capital or to Class A roads". 

The agency is mandated to manage, develop, rehabilitate and maintain national roads.

See also
List of roads in Kenya

References

External links
Website of the Kenya Ministry of Transport and Infrastructure

Transport in Kenya
Economy of Kenya
Geography of Kenya
Induction equation. In magnetohydrodynamics, the induction equation is a partial differential equation that relates the magnetic field and velocity of an electrically conductive fluid such as a plasma. It can be derived from Maxwell's equations and Ohm's law, and plays a major role in plasma physics and astrophysics, especially in dynamo theory.

Mathematical statement
Maxwell's equations describing the Faraday's and Ampere's laws read:

and

where:
 is the electric field.
 is the magnetic field.
 is the vacuum permeability.
 is the electric current density.

The displacement current can be neglected in a plasma as it is negligible compared to the current carried by the free charges. The only exception to this is for exceptionally high frequency phenomena:  for example, for a plasma with a typical electrical conductivity of 107 mho/m, the displacement current is smaller than the free current by a factor of 103 for frequencies below 2 Hz.

The electric field can be related to the current density using the Ohm's law:

where 
 is the velocity field.
 is the electric conductivity of the fluid. 

Combining these three equations, eliminating  and , yields the induction equation for an electrically resistive fluid:

Here  is the magnetic diffusivity (in the literature, the electrical resistivity, defined as , is often identified with the magnetic diffusivity).

If the fluid moves with a typical speed  and a typical length scale , then

The ratio of these quantities, which is a dimensionless parameter, is called the magnetic Reynolds number:

Perfectly-conducting limit
For a fluid with infinite electric conductivity, , the first term in the induction equation vanishes. This is equivalent to a very large magnetic Reynolds number. For example, it can be of order 109 in a typical star. In this case, the fluid can be called a perfect or ideal fluid. So, the induction equation for an ideal conductive fluid such as most astrophysical plasmas is

This is taken to be a good approximation in dynamo theory, used to explain the magnetic field evolution in the astrophysical environments such as stars, galaxies and accretion discs.

Convective limit
More generally, the equation for the perfectly-conducting limit applies in regions of large spatial scale rather than infinite electric conductivity, (i.e., ), as this also makes the magnetic Reynolds number very large such that the diffusion term can be neglected. This limit is called "ideal-MHD" and its most important theorem is Alfvén's theorem (also called the frozen-in flux theorem).

Diffusive limit
For very small magnetic Reynolds numbers, the diffusive term overcomes the convective term. For example, in an electrically resistive fluid with large values of , the magnetic field is diffused away very fast, and the Alfvén's Theorem cannot be applied. This means magnetic energy is dissipated to heat and other types of energy. The induction equation then reads

It is common to define a dissipation time scale  which is the time scale for the dissipation of magnetic energy over a length scale .

See also
 Alfvén's Theorem
 Magnetohydrodynamics
 Maxwell's equations

References

Magnetohydrodynamics
Michael Sadowsky. Michael A. Sadowsky (1902 – December 31, 1967) was a researcher in solid mechanics, particularly the mathematical theory of elasticity and materials science. Born in the Russian Empire, he earned his doctorate in 1927 under the applied mathematician Georg Hamel at Technische Hochschule Berlin-Charlottenburg with a dissertation entitled Spatially periodic solutions in the theory of elasticity (in German). He made contributions in the use of potential functions in elasticity and force transfer mechanisms in composites. Many of his early papers were written in German.

Selected publications

with E. Sternberg:

References

External links

Technische Universität Berlin alumni
Emigrants from the Russian Empire to Germany
1902 births
1967 deaths
20th-century German mathematicians
IAI Ghost. The IAI Ghost is a reconnaissance mini unmanned air vehicle developed in Israel by Israel Aircraft Industries. It is the second tandem-rotor UAV developed by IAI after IAI Panther.

The Ghost appearance is like miniature model of Chinook helicopter. It was developed to support Missions in urban warfare. The quickly deploy-able and easily operate-able system can carry in two backpacks that can be quickly assembled. It has low acoustic, silent propulsion and mission versatility that can perform in day and night. Due to automatic vertical takeoff and landing, it is suitable for use in densely built-up areas. Its functions can be operated by simple man-machine interface.

The main purpose of the Ghost is to intelligence, surveillance and reconnaissance missions, including silent observation, stakeout and covert special operation missions.

Specifications

References

External links 
 Brochure of Ghost Rotary Mini UAS 
 

2011 introductions
Israel Aerospace Industries unmanned aerial vehicles
2010s Israeli military reconnaissance aircraft
Tandem rotor helicopters
Electric aircraft
Aircraft with skid landing gear
Victor Polterovich. Victor Meerovich Polterovich (born 27 December 1937) is a Russian economist. He was one of the leading figures in mathematical economics in the Soviet Union and post-Soviet Russia, and made several important contributions to general equilibrium theory.

Born in Moscow, he obtained a diploma in engineering from Gubkin Russian State University of Oil and Gas in 1962, before taking post-graduate courses at Moscow State University. After an invitation by Aron Katsenelinboigen, Polterovich joined the Central Economic Mathematical Institute in 1966. While remaining a "simple" research fellow, his research contributions gained international recognition. He was a member of the editorial board of the Journal of Mathematical Economics (1985–2009), and an associate editor of Econometrica (1989–95).

Selected publications

References 

1937 births
Living people
Soviet economists
20th-century Russian  economists
Economists from Moscow
Macroeconomists
Moscow State University alumni
Full Members of the Russian Academy of Sciences
Fellows of the Econometric Society
21st-century Russian economists
Sid Meier's Starships. Sid Meier's Starships is a turn-based strategy video game developed by Firaxis Games and published by 2K. It was released on March 12, 2015 for Microsoft Windows, OS X, and iOS. The game is a stand-alone title but shares the same universe as Civilization: Beyond Earth, putting the player in control of a fleet of space-faring craft. The player will use the fleet to explore the galaxy, meeting other human and alien forces, and dealing with problems through a combination of military, diplomatic, and other strategic options. Spacecraft in the fleet can be highly customized for meeting certain goals. The game features cross-connectivity features with Beyond Earth for those that own both titles.

Starships was based on Sid Meier's idea of extending the Beyond Earth setting, in which the player guides the development of one of several human colonies on an alien world, and he considers it a further narrative of that game, exploring the universe and encountering other human colonies and threats it may hold. In his concept, Meier wanted to focus on starship creation, including highly configurable ships, and space combat, while providing the player with "a universe filled with interstellar adventure, diplomacy, and exploration". The game was developed by Meier and a small team at Firaxis.

Reception

The iOS version received "generally favorable reviews", while the PC version received "mixed" reviews, according to the review aggregation website Metacritic. IGN said of the same PC version, "Sid Meier's Starships produces a few good tactical battles before its AI loses steam and its strategy gets frustrating."

The Escapist gave the PC version a score of four stars out of five, saying that it "lacks the strategic depth of Civilization, but the added tactical layer, and shorter game times make it a fair substitute, especially if you're looking for bite-sized strategy." National Post gave it a similar score of eight out of ten, saying that the game "may lack the complexity and nuance of other strategy games, and it feels a bit rough around the edges in places, but its accessibility, terrific turn-based combat, and bite-sized duration combine to create a tempting alternative to a multi-evening marathon campaign." Metro gave it a score of seven out of ten, saying, "Fast-paced and accessible are not words commonly used to describe turn-based strategy games, but Sid Meier's latest is a fun, breezy strategic time killer." GameSpot gave the PC version four stars out of ten, saying "it's a strategy game without strategy, enabling you to sleepwalk your way to triumph."

References

External links
 Sid Meier's video interview with French newspaper Le Point, about Starships and other games, in English after the 20-seconds intro (February 25, 2015). 
 

2015 video games
2K games
Firaxis Games games
Fiction about interstellar travel
IOS games
Multiplayer and single-player video games
MacOS games
Science fiction video games
Single-player video games
Starships
Video games developed in the United States
Windows games
Sverige (yacht). Sverige is a Swedish 12 Metre class yacht. It was by designed by Pelle Petterson and built by Enoch & Elfstedt.

Sverige competed in the 1977 Herbert Pell Cup and the 1980 Herbert Pell Cup, helmed by Pelle Petterson. Both times it was beaten by Australia.

References

12-metre class yachts
Sailing yachts built in Sweden
Sailing yachts designed by Pelle Pettersson
1970s sailing yachts
Sailing yachts of Sweden
Louis Vuitton Cup yachts
1977 ships
American Rover. American Rover is a tall ship that operates public and private passenger harbor cruises from Norfolk, Virginia, United States. 

Her steel hull was built in Panama City, Florida in 1985 and she was fitted out in the Willoughby area of Norfolk, Virginia. American Rover measures 98 GT and has a hull length of  and  overall. Her sail area totals 5,000 square feet, and she has twin auxiliary engines and screws.

When she entered service in 1986, she was the largest three-masted, passenger-carrying topsail schooner in the US. Her design, by Merritt Walter, is based on 19th century cargo schooners of the East coast of the United States and Chesapeake Bay.

References

External links
 American Rover website

1985 ships
Tall ships of the United States
Schooners of the United States
Ships built in Panama City, Florida
Ships built in Norfolk, Virginia
Bolesław Konorski. Bolesław Konorski (14 April 1892 – 12 February 1986) was a Polish engineer and electrotechnician. He was Rector of the Lodz University of Technology in 1952–1953.

He graduated from  the Vienna University of Technology in 1918. In 1946 he started work at the Lodz University of Technology (TUL), where he largely contributed to the organising of the didactic process for electricians. He was a founder and then Head of the Fundamentals of Electrotechnology Department. From 1948 to 1952 he was Pro-Rector of the TUL, then Rector in 1952–1953. He became a full professor in 1951.

Konorski published nearly 100 works in the field of theoretical electrotechnology, in which he made a generalisation of Coulomb's law and specified and expanded the concept of molecular capacity in power cables. His four-volume monograph on the fundamentals of electrotechnology and theoretical electrotechnology was the first academic course-book in the field in post-war Poland. He also published a book on the elements of relativity theory and relativistic mechanics and electrodynamics. He was an author and editor of Kalendarzyk Elektrotechniczny.

Konorski was a co-founder of the Polish Association of Theoretical and Applied Electrotechnology, a member of the Polish Academy of Sciences' Science Council in the Institute of Basic Problems in Technology, and a member of the Lodz Scientific Association.

From 1952 to 1957 he was a member of the Central Membership Committee. In 1979 he became a member of Scientific Training Association (Towarzystwo Kursów Naukowych).

References

Bibliography
 
 

1892 births
1986 deaths
Engineers from Łódź
People from Piotrków Governorate
University of Vienna alumni
Academic staff of Łódź University of Technology
Polish electrical engineers
Polish United Workers' Party members
Recipients of the Medal of the 10th Anniversary of the People's Republic of Poland
Antoon Kolen. Anthonius Wilhelmus Johannes (Antoon) Kolen (22 May 1953 – 3 October 2004) was a Dutch mathematician and Professor at the Maastricht University, in the Department of Quantitative Economics. He is known for his work on dynamic programming, such as interval scheduling and mathematical optimization.

Biography 
Born in Tilburg, Kolen obtained his engineering degree from the Eindhoven University of Technology in 1978. In 1982, he obtained his PhD at the Centrum Wiskunde & Informatica, University of Amsterdam under Gijsbert de Leve and Jan Karel Lenstra with the thesis, entitled "Location Problems on Trees and in the Rectilinear Plane."

After his graduation, Kolen started his academic career at the Econometric Institute of Erasmus University Rotterdam. Late 1980s he moved to the Maastricht University, where he was appointed Professor at the Department of Quantitative Economics and head of its operations research group.

His PhD students at the Erasmus University Rotterdam were Leo Kroon (graduated in 1990), Albert Wagelmans (1990), C. Stan van Hoesel (1991), Wim Pijls (1991), Peter Verbeek (1991), and A. Woerlee (1991);  W. Hennen at the Wageningen University and Research Centre (graduated in 1995), and at the Maastricht University Alwin Oerlemans (graduated in 1992), Ron van der Wal (1995), Maarten Oosten (1996), Jons van de Klundert (1996), Robert van de Leensel (1999), Arie Koster (1999), and Alexander Grigoriev (2003).

Selected publications 
 Antoon Kolen. Location Problems on Trees and in the Rectilinear Plane. PhD thesis, Universiteit van Amsterdam, 1982.
 Kolen, Antoon WJ, and Arie Tamir. Covering problems. Econometric Institute, 1984.

Articles, a selection:
 Brouwer, Andries E., and Antoon WJ Kolen. "A super-balanced hypergraph has a nest point." Stichting Mathematisch Centrum. Zuivere Wiskunde ZW 146/80 (1980): 1-7.
 Hoffman, Alan J., A. W. J. Kolen, and Michel Sakarovitch. "Totally-balanced and greedy matrices." SIAM Journal on Algebraic and Discrete Methods 6.4 (1985): 721-730.
 Kolen, Antoon WJ, A. H. G. Rinnooy Kan, and H. W. J. M. Trienekens. "Vehicle routing with time windows." Operations Research 35.2 (1987): 266-273.
 Wagelmans, Albert, Stan Van Hoesel, and Antoon Kolen. "Economic lot sizing: an O (n log n) algorithm that runs in linear time in the Wagner-Whitin case." Operations Research 40.1-Supplement - 1 (1992): pp. 145–156.
 Koster, Arie MCA, Stan P.M. Van Hoesel, and Antoon WJ Kolen. "The partial constraint satisfaction problem: Facets and lifting theorems." Operations research letters 23.3 (1998): 89-97.
 Kolen, Antoon. "A genetic algorithm for the partial binary constraint satisfaction problem: an application to a frequency assignment problem." Statistica Neerlandica 61.1 (2007): 4-15.

References

External links 
 Antoon Kolen in Statistica Neerlandica, 2007

1953 births
2004 deaths
Dutch mathematicians
Dutch operations researchers
Eindhoven University of Technology alumni
University of Amsterdam alumni
Academic staff of Erasmus University Rotterdam
Academic staff of Maastricht University
People from Tilburg
Hendrich's Drop Forge. The Hendrich's Drop Forge part of the LVR Industriemuseum is a museum in Solingen (), a city in North Rhine-Westphalia, Germany. It is located on the northern edge of the region called Bergisches Land, south of the Ruhr.
The museum is an Anchor point on the European Route of Industrial Heritage.

Context
The Hendrichs family firm was founded in 1886 during an economic boom in Solingen. Solingen in the “Bergisches Land” had turned out scissors, knives and weapons since the Middle Ages. External conditions were ideal as there were limitless supplies of iron ore from the hills while the surrounding forests provided enough fuel to keep the fires burning. The River Wupper and its many tributaries provided the necessary hydraulic power for all the forging and grinding operations. Solingen's drop forges caused the town to become the world's largest producer of scissors.

History
The Hendrichs Drop Forge in Solingen is around 120 years old and it continued as a commercial concern producing scissors until 1986. The LVR Industrial Museum took over the complete site including the buildings, technical equipment and nine members of staff.

Process
The heavy, block-like forging dies were responsible for this: precision tools made of top quality steel into which the hollow outline of a scissor blade had been carved. The Hendrichs factory contained 33 drop hammers, which made it the largest drop forge in the area. The hammer only needed to be dropped a maximum of four times to forge a scissor blade from a narrow slab of steel.

References
Notes

Footnotes

External links

 Official Website

Industry museums in Germany
Steel industry of Germany
European Route of Industrial Heritage Anchor Points
Solingen
Leduc RL.21. The Leduc RL.21 was a single engine, single seat light aircraft built in the late 1950s in France.  Designed to achieve high speeds from modest engine power, it set seven class records in the early 1960s.

Design and development
Between 1939 and 1975 the amateur aircraft designer and builder René Leduc (not the ramjet designer of the same name) completed and flew five different lightplanes, two of which set records in their class.  The RL.21 was a low wing monoplane with its wings braced to the upper fuselage by a pair of inverted-V struts. It was powered by a  SNECMA-Régnier 4L-00 four cylinder inverted air-cooled inline engine driving a two blade propeller.  A low, smoothly streamlined canopy covered the single seat cockpit and merged aft into a raised rear fuselage.  The empennage was conventional.  The RL.21 had a tailwheel undercarriage with spatted main wheels on cantilever legs, mounted on the wings approximately below the ends of the wing struts.

Leduc built the RL.21 over a period of six years with assistance from Sud Aviation and from the Nantes Technical School. It flew for the first time in August 1960. Between late 1960 and early 1967 it set seven records in its C1a and C1b categories, respectively for aircraft with maximum take-off weights below  and between .  The earliest were for speeds of  and  for the two classes around a  closed circuit  and the last at  and  over a  closed circuit. Throughout these flights the pilot was Raymond Davy.

Specifications

References

1960s French sport aircraft
RL.21
Single-engined tractor aircraft
Low-wing aircraft
Aircraft first flown in 1960
Mechanical device test stands. A mechanical device test stand is one specific type of test stand. It is a facility used to develop, characterize and test mechanical components. The facility allows for the testing of the component and, it offers measurement of several physical variables associated to the functionality of the component. Such components could be electromechanical, motors or tools. The intended use of the test stand is for compliance testing of predetermined desired values and fatigue testing.
A sophisticated mechanical component test stand houses several integrated measurement and control (imc) components, such as sensors, data acquisition devices and actuators to control the component. The sensors measure several physical variables, such as:

 Strain/multi-axial strain 
 Mechanical stress
 Rigidity/stiffness
 Angle
 Vibration/oscillation signals

Information gathered from the sensors is processed and logged through the use of data acquisition systems. Actuators allow for attaining a desired state. Test stands for mechanical devices are often custom-built according to the requirements of the customer. They often include a feedback control system.

Applications for mechanical device test stands

 Research and Development of components, motors and tools (e.g., the testing of sun roofs, engine hoods, welding equipment. etc.), typically found in factory environments.
 End of production line at an OEM factory. Changing of tested components can take place automatically.

Mechanical device testing for research and development

Research and Development (R&D) activities on mechanical components have necessitated sophisticated mechanical component test stands. For example, automobile OEMs or aviation OEMs are usually interested in developing mechanical components that meet the following objectives:
 Provide high durability
 High efficiency
 High performance/quality
 Keep costs down

Consequently, R&D mechanical component test stands perform a variety of exercises including measurement, control and recording of several relevant engine variables.

Typical tests include
 Determine efficiency
 Structural analysis
 Determine durability: e.g., aging tests
 Gain further knowledge about the mechanical component
 Fourier analysis
 Order analysis
 Fatigue analysis

See also
 engine test stand
 electric motor test stand

References

Mechanical tests
Test equipment