omniomni/omni-engineering huggingface dataset:
Brownout (software engineering). Brownout in software engineering is a technique that involves disabling certain features of an application.

Description 
Brownout is used to increase the robustness of an application to computing capacity shortage. If too many users are simultaneously accessing an application hosted online, the underlying computing infrastructure may become overloaded, rendering the application unresponsive. Users are likely to abandon the application and switch to competing alternatives, hence incurring long-term revenue loss. To better deal with such a situation, the application can be given brownout capabilities: The application will disable certain features – e.g., an online shop will no longer display recommendations of related products – to avoid overload. Although reducing features generally has a negative impact on the short-term revenue of the application owner, long-term revenue loss can be avoided.

The technique is inspired by brownouts in power grids, which consists in reducing the power grid's voltage in case electricity demand exceeds production. Some consumers, such as incandescent light bulbs, will dim – hence originating the term – and draw less power, thus helping match demand with production. Similarly, a brownout application helps match its computing capacity requirements to what is available on the target infrastructure. 

Brownout complements elasticity. The former can help the application withstand short-term capacity shortage, but does so without changing the capacity available to the application. In contrast, elasticity consists of adding (or removing) capacity to the application, preferably in advance, so as to avoid capacity shortage altogether. The two techniques can be combined; e.g., brownout is triggered when the number of users increases unexpectedly until elasticity can be triggered, the latter usually requiring minutes to show an effect.

Brownout is relatively non-intrusive for the developer, for example, it can be implemented as an advice in aspect-oriented programming. However, surrounding components, such as load-balancers, need to be made brownout-aware to distinguish between cases where an application is running normally and cases where the application maintains a low response time by triggering brownout.

References 

Software engineering
Cloud computing
Sentetsu Jiha class railcars. The Jiha (Japanese ジハ, Korean 디하) class railcars were a pair of Diesel-powered railcars of the Chosen Government Railway (Sentetsu). After Liberation, they all remained in the South, where they were operated by the Korean National Railroad; none were preserved.

Following the experiences with the Keha class petrol railcars, in 1931 Sentetsu decided, in the interests of reducing fuel costs, to design and introduce a railcar powered by a diesel engine. Two Jiha1 (ジハ1) diesel railcars were therefore built in 1933 at the Gyeongseong Works.

The structure and interior of the diesel railcars was similar to the gasoline-powered Keha railcars, but they were more streamlined at both ends, and were powered by a German Motoren Werke Mannheim SS17S  diesel engine with cylinders of  bore; the pistons were made of light alloy, and the cylinder head was cast iron. The fuel injector and the injection timing mechanism were almost identical to those used today. The engines were imported from Germany and were installed at Gyeongseong.

The diesel railcars, producing much less smoke than the gasoline-powered ones, were well received by the public and became quite popular. However, increasing oil shortages during the Pacific War led to their use being curtailed. Therefore, the engines were modified to use other fuels such as alcohol and benzene; experiments were conducted with wood gas, as well. However, these proved unsatisfactory, and the experiments ceased in 1944.

Both railcars survived the Pacific War, remaining in the South after the partition of Korea, where they were operated by the Korean National Railroad until the early 1960s, when they were replaced by the DC-class diesel-hydraulic railcars built by Niigata Sharyō, Kinki Sharyō and Kawasaki.

References

Railcars of Korea
Railcars of South Korea
Railway locomotives introduced in 1933
Gyeongseong Works locomotives
McIntosh & Seymour. McIntosh & Seymour was an American manufacturer of steam and internal combustion engines during the late 19th and early 20th centuries.

The company was founded in 1886, and was based in Auburn, New York. It developed and sold a wide variety of steam engines through the end of the 1800s, and by 1910 had begun to build diesel engines to a design from the Swedish company Aktiebolaget Atlas.  It primarily produced large engines for stationary generator and marine applications. In the 1920s, McIntosh & Seymour was an early builder of diesel engines for use in railroad locomotives, providing an engine to the American Locomotive Company (Alco) for an experimental locomotive.  In 1929, Alco purchased McIntosh & Seymour, and operated it as a subsidiary for some time before the name vanished.  Under Alco ownership, McIntosh & Seymour designed and built Alco's first production diesel engine, the 531.

The company's archives are held by the Smithsonian Institution, covering the period from circa 1886-1939.

References

American companies established in 1886
Manufacturing companies based in New York (state)
Manufacturing companies disestablished in 1929
Steam engine manufacturers
Diesel engine manufacturers
Locomotive engine manufacturers
Engine manufacturers of the United States
Auburn, New York
McIntosh & Seymour 531. The McIntosh & Seymour 531 was a diesel prime mover built by McIntosh & Seymour for use in railroad locomotives built by its parent company, the American Locomotive Company (Alco).

The 531 engine was designed and introduced in 1931.  It was a six cylinder engine, with a bore of  and a stroke of .  It was produced in naturally aspirated and turbocharged variants, making 600 and 900 horsepower, respectively.  It was primarily used in Alco's line of HH series switcher locomotives, as well as the Rebel passenger trains.  It was replaced by the 538 engine, which had a similar output as the 531 but with upgraded components.

References

Notes

Bibliography

Diesel locomotive engines
Flyway (disambiguation). A flyway is a bird migration flight path

Flyway may also refer to:
 Flyway (magazine), Iowa State University journal
 Flyway (software), a Java database migration framework
 Flyways Linhas Aéreas, a Brazilian airline
 Flyway Club, a shooting club in North Carolina, US
 Flyway Film Festival, a festival in Pepin, Wisconsin, US

See also
 Airway (disambiguation)
 Flight plan (disambiguation)
 Flightpath (disambiguation)
 Fly Away (disambiguation)
 Skyway (disambiguation)
Tripod (laboratory). A laboratory tripod is a three-legged platform used to support flasks and beakers. Tripods are usually made of stainless steel or aluminium and made light-weight for efficient portability within the lab. Often a wire gauze is placed on top of the tripod to provide a flat base for glassware. Tripods are generally tall enough for a bunsen burner to be placed underneath.

Variations
There are several different designs. The top is commonly triangular or circular, and sometimes the three legs can be removed and adjusted depending on the preferences of the user.

Usage
A laboratory tripod is most commonly used in middle and high schools for basic heating experiments. However, tripods and bunsen burners have been made obsolete by hot plates, which are considered to be safer since there is no direct contact with the flame.

See also 
 Bunsen burner
 Hot plate
 Tripod
 Wire gauze

References

Laboratory equipment
Scandinavian Academy of Aeronautics. Scandinavian Academy of Aeronautics () was a Swedish  accredited college specializing in aerospace engineering and avionics, situated in Gothenburg from 1973 and in Karlsborg from 1998 to 2003. The college was a major contributor of engineers and researchers in partnership with the aerospace industry, major airliners and other universities.

History
Scandinavian Academy of Aeronautics was founded and opened by Runo Ewe-Ericson and Percival Ewe-Ericson in 1973 with its main campus situated in Bellmannsgatan 10, Gothenburg. For a short period in the mid 1990s its campus location was in Vestre Hamngatan,  Gothenburg, before it moved to Karlsborg in 1998 until 2003. The number of  students was radically reduced when the school moved to Karlsborg, and as co-founder and acting principal Percival Ewe-Ericson passed away in 2002 the school was closed down the following year. The shutdown led to the school filing a subpoena against the city of Karlsborg claiming they did not receive the funds promised for the establishing of the new campus.

In 2003 Lillian Syrene Ewe-Ericson founded an entity in cooperation with the Gothenburg Aviation Museum () to preserve the cultural heritage the school has contributed to Sweden's aeronautical history.

Courses
Scandinavian Academy of Aeronautics offered a range of courses focused on aerospace engineering and avionics including:

Aeronautics
Combustion engine technologies
Jet engine Construction
Helicopter mechanics
Water Engines and Pumps
Machine theory
Avionics
Electronics
General Chemistry
Combustion chemistry
Thermodynamics
Computer Science
Solid mechanics
Materials science
Production Technologies
Mathematics
Physics
Technical English
Technical drawing
Business Economics
Work Psychology and Management
Ecology and Environmental Care

Accreditations
Accredited for financial support to students from the Swedish government.
Accredited for financial support to students from the Norwegian government. 
Consultative body for Swedish government on qualified higher vocational education
Accredited for financial support to students from Adlerbretska Premiestiftelsen

Admissions
General admission requirements; senior high school graduate or equivalent.

Principals
Runo Ewe-Ericson
Percival Ewe-Ericson

References 

Schools in Sweden
N-World. N-World is a 3D graphics package developed by Nichimen Graphics in the 1990s, for Silicon Graphics and Windows NT workstations. Intended primarily for video game content creation, it has polygon modeling tools, 2D and 3D paint, scripting, color reduction, and exporters for several popular game consoles.

After its initial release on Windows NT, N-World was renamed  Mirai. The winged edge 3D modeler in N-World inspired the development at Nichimen Graphics of Nendo, a standalone 3D modeler, which in turn inspired the open source modeler Wings 3D.

History
N-World originated with Symbolics, a computer manufacturer notable for producing Lisp-based systems in the 1980s. Among the software packages that were produced for Symbolics computers are S-Graphics, a 3D animation suite that includes modules for polygon modeling, dynamics, paint, and rendering — titled S-Geometry, S-Dynamics, S-Paint, and S-Render, respectively. In 1992, Japanese trading company Nichimen Corporation purchased the rights to S-Graphics, ported it to Silicon Graphics IRIX, and marketed it as N-World.

N-World retains the Lisp-based underpinnings of its predecessor, but was targeted at interactive content producers, with features useful for game developers. It was priced at  for the full suite, later reduced to  when ported to Windows NT in 1997.

N-World was used to create graphics for many console games in the 1990s, including Super Mario 64 and Final Fantasy VII. It was superseded by Mirai in 1999.

Features

The N-World package, like its predecessor S-Graphics, is divided into several components:

 N-Geometry: 3D polygon-based modeling tools, including smoothing, "magnet" geometry editing, and instancing.
 N-Dynamics: Animation tools including scripting, curve-based animation, and skeletal animation.
 N-Render: Surfacing and rendering tools with ray tracing and materials output to various game console formats.
 N-Paint: 2D and 3D paint with mattes, effects, color reduction, and a visual VRAM editor for PlayStation.
 Game Tools: Utilities for game developers, including exporters for PlayStation, Nintendo 64, and Saturn consoles.

Credits
The following games were created using N-World.

 Super Mario 64
 Final Fantasy VII
 Gran Turismo
 Bomberman 64
 Magic the Gathering
 NBA Jam Extreme
 NHL Breakaway
 PaRappa the Rapper
 MediEvil
 WWF '98
 Derby Stallion (PS1)
 Shin Kaitei Gunkan
 AeroGauge
 Virtual ProWrestling
 Power Ranger Pin Ball
 Spider
 Motor Toon Grand Prix
 Beast Wars: Transformers
 Overblood
 Enemy Zero
 Forsaken
 64 Ōzumō
 Crash Bandicoot

  Rap Stars Online

References

External links 
 Nichimen Graphics N-World 3 discussion thread on Nekochan.net

3D graphics software
IRIX software
1990s software
Graphics software
Common Lisp (programming language) software
Renfe Class 447. The Renfe Class 447 is a class of electric multiple unit trains built by CAF, Alstom, Siemens, ABB, and Adtranz for Renfe Cercanías, Spain's commuter railway networks. The first units entered service in 1993.

History
In the early 1980s, Cercanías services started gaining importance in cities like Madrid and existing units, essentially Renfe Class 440, began to become insufficient. For this reason, the design of a new train model began its development. This was materialized in a prototype, Renfe Class 445, built in 1984 and tested in Madrid and Barcelona's networks until year 1990. After this, Renfe Class 446 and 447 started their manufacture process in 1989 and 1992 respectively, the second of which added some improvements to the original model. 
The only visually perceivable difference between 446 and 447 is that, in the first, letters "R" and "M" in the numbering system are displayed red and white respectively, while in 447, they're both yellow. This numbering is found in the top left corner of the front of the motor units, and on the sides of the Remolque units.

Technical details
Class 447 units use 3 kV DC overhead catenary line electric traction. The maximum speed of Class 447 units in service is 120 km/h. Both speed and acceleration were improved from its predecessor, Class 446. Due to the difference in performance between 447 and its counterpart, the older model is set for lines where the distance between stations is shorter (1-2 km), given its reduced maximum speed (100 km/h instead of 447's 120 km/h) didn't affect the time between stations.

Cities and routes
Class 447 units operate on the following networks:
 Cercanías Murcia/Alicante
 Rodalies de Catalunya
 Cercanías Valencia
 Cercanías San Sebastián
 Cercanías Cantabria
 Rodalia de Girona (Rodalies de Catalunya)
 Rodalia del Camp de Tarragona (Rodalies de Catalunya)
 Regional services in Catalunya
 Cercanías Madrid (until 2018)

Gallery

See also

Renfe Class 446
Renfe
Cercanías
Rodalies de Catalunya

References

External links

Ferropedia - Renfe Serie 447 (Spanish)
Renfe - Our Trains
Complete data sheet

CAF multiple units
Cercanías
Renfe multiple units
Siemens multiple units
3000 V DC multiple units
Train-related introductions in 1993
B&F Fk131 Bücker Jungmann. The B&F Fk131 Bücker Jungmann () is a German ultralight and homebuilt aircraft with the project design headed by B&F Technik Vertriebs GmbH of Speyer and the aircraft produced by Podesva Air of the Czech Republic, introduced at the AERO Friedrichshafen show in 2013. The aircraft was built in a production run of ten aircraft and supplied complete and ready-to-fly. By 2017 it was no longer advertised for sale.

The aircraft is a replica of the 1934 Bücker Bü 131 Jungmann.

Design and development
The project to produce a batch of Bücker Bü 131 Jungmann replicas was headed by B&F's Peter Funk. Production commenced in 2013 with an initial batch of ten aircraft. The aircraft were to be eligible for the Fédération Aéronautique Internationale microlight rules at a gross weight of  and experimental aircraft rules at a gross weight of .

The design features a wire and strut-braced biplane layout, a two-seats in tandem open cockpit, fixed conventional landing gear and a single engine in tractor configuration.

The aircraft duplicates the original 1934 Bü 131's construction. Its  span wing is supported by cabane struts and a single set of parallel interplane struts outboard on the wings, with wire bracing. The standard engine used is the  Walter Micron IIIC four-stroke, inverted four cylinder, air-cooled powerplant.

Specifications (Fk131)

Notes

References

Fk131 Bücker Jungmann
2010s German ultralight aircraft
Single-engined tractor aircraft
Replica aircraft
Aircraft with fixed conventional landing gear
Single-engined piston aircraft
VEF I-14. The VEF I-14 was a Latvian Air Force trainer aircraft prototype, built by VEF.

Design and development 
Kārlis Irbītis began work on the I-14 in 1936 in response to an order placed by the Latvian Air Force for a new trainer aircraft.  Taking inspiration from the British Miles aircraft, the I-14 was a low-wing monoplane with fixed, conventional landing gear.  The single pilot sat in an enclosed cockpit.  It was powered by a 200 hp Menasco B6S Buccaneer.

Operational history 
The I-14 made its maiden flight on 19 November 1937.  On 23 April 1938, the aircraft was destroyed in a crash, its pilot, Bandenieks, was unhurt.  Development of the I-14 was abandoned in favor of the more advanced VEF I-15.

Specifications (I-14)

References 

1930s Latvian military trainer aircraft
Low-wing aircraft
Single-engined tractor aircraft
VEF aircraft
Triangulene. Triangulene (also known as Clar's hydrocarbon) is the smallest triplet-ground-state polybenzenoid. It exists as a biradical with the chemical formula . It was first hypothesized by Czech chemist Erich Clar in 1953. Its first confirmed synthesis was published in a February 2017 issue of Nature Nanotechnology, in a project led by researchers David Fox and Anish Mistry at the University of Warwick in collaboration with IBM. Other attempts by Japanese researchers have been successful only in making substituted triangulene derivatives.

A six-step synthesis yielded two isomers of dihydrotriangulene which were then deposited on xenon or copper base. The researchers used a combined scanning tunneling and atomic force microscope (STM/AFM) to remove individual hydrogen atoms. The synthesized molecule of triangulene remained stable at high-vacuum low-temperature conditions for four days, giving the scientists plenty of time to characterize it (also using STM/AFM).

[n]Triangulenes 
Triangulene, as defined here, is a member of a wider class of [n]triangulenes, where n is the number of hexagons along an edge of the molecule. Thus, triangulene may also be referred to as [3]triangulene.

Theory 
A tight-binding description of the molecular orbitals of [n]triangulenes  predicts that [n]triangulenes  have (n − 1) unpaired electrons, which are associated to  (n − 1) non-bonding states.  When electron–electron interactions are included, theory predicts that the ground state total spin quantum number S of [n]triangulenes is S = . Thus, [3]triangulenes are predicted to have an S = 1 ground state. The intramolecular exchange interaction in triangulene, which determines the energy difference between the S = 1 ground state and the S = 0 excited state, is predicted to be the largest among all polycyclic aromatic hydrocarbon (PAH) diradicals, due to maximum overlap of the wave function of the unpaired electrons.

The ground state spin of [n]triangulenes can be rationalized in terms of a theorem by Elliot H. Lieb, which relates, for a bipartite lattice, the ground state spin of the Hubbard model at half filling to the sublattice imbalance.

Experiments 
So far, the ultra-high vacuum on-surface syntheses of [n]triangulenes with n = 3, 4, 5 and 7 (the hitherto largest triangulene homologue) have been reported. In addition, the on-surface synthesis of [3]triangulene dimers has also been reported, where inelastic electron tunneling spectroscopy provides a direct evidence of a strong antiferromagnetic coupling between the triangulenes. In 2021, an international team of researchers reported the fabrication of [3]triangulene-based quantum spin chains on a gold surface, where signatures of both spin fractionalization and Haldane gap were observed.

References 

Polycyclic aromatic hydrocarbons
Free radicals
Banihal Qazigund Road Tunnel. Banihal Qazigund Road Tunnel is a road tunnel at elevation of  in the Union Territory of Jammu and Kashmir in India, below the Banihal Pass in the Pir Panjal mountain range in lower Himalayas, on National Highway 44. In July 2011 , Mr CP Joshi than Union Minister for Road Transport and Highways along with CM of JK Omar Abdullah and Union Health minister Mr Ghulam Nabi Azad laid foundation stone of this tunnel.Its construction started in 2011 and was completed in 2021. It is one of the longest tunnels in India, with a length of . The tunnel reduces the distance between the cities of Srinagar and Jammu by 16 km. It also reduces the travel time between these cities from 6 hours to 5.5 hours.

The tunnel consists of two parallel tunnels, one for each direction of travel. Each tunnel is  wide, and each has two lanes of road. The two tunnels are interconnected by a passage every  for maintenance and emergency evacuation. The tunnel has forced ventilation to extract smoke and stale air and infuse fresh air. It has state-of-the-art monitoring and control systems for security. Built at a cost of ₹2,100 crore, citizens pay a toll to use the tunnel.

Construction

Construction of the tunnel started in 2011 along with the project to widen NH 44 (which was known as NH 1A before all the national highways were renumbered in the year 2010) to four lanes. The existing road tunnel below the Banihal pass (Jawahar tunnel), has been a bottleneck on the road due to its elevation of  and limited traffic capacity. The new tunnel's average elevation at 1,790 m is 400 m lower than the existing Jawahar tunnel's elevation, making it less prone to avalanches. The tunnel has reduced the road distance between Banihal and Qazigund by 16 km (10 mile).

 As of May 2016, 7.2 km of the 8.5 km had been excavated.
 As of February 2017, the tunnel excavation was close to completion.
 February 2018: Boring work of one tunnel had been completed.
 May 2018: Boring of the entire 8.5 km tunnel was completed on 20 May 2018.
 Jan 2019:Tunnel may open for traffic by March 2020.
 November 2019: Work progressing at slow pace; tunnel to be opened for traffic in March 2021.
25 February 2021:Tunnel likely to open for traffic in April 2021
 5 April 2021: opening delayed until end of April 2021.
July 2021: Tunnel could be inaugurated on the independence day by Prime Minister Narendra Modi.
August 2021: Tunnel was opened by the Road Transport and Highways Minister, Nitin Gadkari.

Location
The Southern portal (end) of the tunnel is at  and the Northern portal (end) of the tunnel is at .

Safety measures

The tunnel is made on build–operate–transfer basis. It is built with an exhaust system to remove gas and bring in fresh air. It has 126 jet fans, 234 CCTV cameras and a firefighting system installed.

See also
 Jawahar Tunnel
 Dr. Syama Prasad Mookerjee Tunnel
 Chattergala Tunnel
 Zoji-la Tunnel
 Z-Morh Tunnel
 Pir Panjal Railway Tunnel
 NH 44 (former name NH 1A before renumbering of all national highways)

References

Road tunnels in Jammu and Kashmir
Road infrastructure in India
Road tunnels in India
Ramban district
Anantnag district