omniomni/omni-engineering huggingface dataset:
Notch (engineering). In mechanical engineering and materials science, a notch refers to a V-shaped, U-shaped, or semi-circular defect deliberately introduced into a planar material. In structural components, a notch causes a stress concentration which can result in the initiation and growth of fatigue cracks. Notches are used in materials characterization to determine fracture mechanics related properties such as fracture toughness and rates of fatigue crack growth. 

Notches are commonly used in material impact tests where a morphological crack of a controlled origin is necessary to achieve standardized characterization of fracture resistance of the material. The most common is the Charpy impact test, which uses a pendulum hammer (striker) to strike a horizontal notched specimen. The height of its subsequent swing-through is used to determine the energy absorbed during fracture. The Izod impact strength test uses a circular notched vertical specimen in a cantilever configuration. Charpy testing is conducting with U- or V-notches whereby the striker contacts the specimen directly behind the notch, whereas the now largely obsolete Izod method involves a semi-circular notch facing the striker. Notched specimens are used in other characterization protocols, such as tensile and fatigue tests.

Types of notches
The type of notch introduced to a specimen depends on the material and characterization employed. For standardized testing of fracture toughness by the Charpy impact method, specimen and notch dimensions are most often taken from American standard ASTM E23, or British standard BS EN ISO 148-1:2009. For all notch types, a key parameter in governing stress concentration and failure in notched materials is the notch tip curvature or radius.

Sharp tipped V-shaped notches are often used in standard fracture toughness testing for ductile materials, polymers and for the characterization of weld strength. The application of such notches for hard-steels is problematic due to sensitivity to grain alignment, which is why torsional testing may be applied for such materials instead.

A U notch is an elongated notch having a round notch-tip, being deeper than it is wide. This notch is also often referred to as C-notch, and is the most widely form of introduced notch, due to the repeatability of results obtained from notch specimens. Correlating U-Notch performance to V-Notch equivalent is challenging and is carried out on a case by case basis, there is no standardized correlation between performance values obtained with the two notch types.

A keyhole notch is typically considered as a slit ending in a hole of a given radius. This type of notch is most often considered in numerical models. Fracture toughness results obtained from keyhole notch testing are often higher than those obtained from V-notched or pre-cracked specimens.

See also

 Charpy impact test

References

Fracture mechanics
Arsonium. The arsonium cation is a positively charged polyatomic ion with the chemical formula . An arsonium salt is a salt containing either the arsonium () cation, such as arsonium bromide () and arsonium iodide (), which can be synthesized by reacting arsine with hydrogen bromide or hydrogen iodide. Or more commonly, as organic derivative such as the quaternary arsonium salts  (CAS: , hydrate form) and the zwitterionic compound arsenobetaine.

References 

Arsenic(−III) compounds
Cations
IBM 8750 Business Communication System. The IBM 8750 Business Communications System was a voice and data switching system PABX, suitable for medium to large numbers of extensions, used on customer premises." The 8750 was the European version of the IBM 9751, also a ROLM design. 

In 1984, IBM bought the American company ROLM. In 1987 IBM started to market the ROLM-derived IBM 8750 in Austria, Belgium, France, Germany, Italy, Luxemburg, and the UK. Principally for homologation, a few had been installed in IBM locations, such as IBM Havant in England – however none were installed in customer locations.

The 8750 had from 91 to 3000 telephone extensions; up to 1000 simultaneous conversations; a computer based on a Motorola 68020; up to 16 IBM 8755 Operator Consoles; a 30MB fixed disk; main/satellite working with IBM 3750 and 1750 Switching Systems; digital trunks in Belgium, Italy and the UK; and ISDN and Systems Network Architecture (SNA) networks. 

IBM later sold ROLM to Siemens who then continued to market the 8750.

See also
IBM 1750, 2750 and 3750 Switching Systems

References 

Telephone exchange equipment
8750
8750
VRT 300. The VRT 300 () is a Russian unmanned helicopter. It was introduced at the MAKS airshow in 2017.

It was constructed for arctic ice patrols in support of safe maritime navigation. Another version of the VRT300, Opticvision, boasts an increased range of flight for monitoring and remote probing.

Specifications 

 Maximum take-off weight: 300 kg
 Payload weight: 70 kg
 Maximum range of communication with line of sight at flight altitude: 100 km

See also 
VRT 500
Kamov Ka-137

References 

2010s Russian aircraft
3ω-method. The 3ω-method (3 omega method) or 3ω-technique, is a measurement method for determining the thermal conductivities of bulk material (i.e. solid or liquid) and thin layers.  The process involves a metal heater applied to the sample that is heated periodically.  The temperature oscillations thus produced are then measured.  The thermal conductivity and thermal diffusivity of the sample can be determined from their frequency dependence.

Theory
The 3ω-method can be accomplished by depositing a thin metal structure (generally a wire or a film) onto the sample to function as a resistive heater and a resistance temperature detector (RTD). The heater is driven with AC current at frequency ω, which induces periodic joule heating at frequency 2ω (since ) due to the oscillation of the AC signal during a single period.

There will be some delay between the heating of the sample and the temperature response which is dependent upon the thermal properties of the sensor/sample. This temperature response is measured by logging the amplitude and phase delay of the AC voltage signal from the heater across a range of frequencies (generally accomplished using a lock-in-amplifier).

Note, the phase delay of the signal is the lag between the heating signal and the temperature response. The measured voltage will contain both the fundamental and third harmonic components (ω and 3ω respectively), because the Joule heating of the metal structure induces oscillations in its resistance with frequency 2ω due to the temperature coefficient of resistance (TCR) of the metal heater/sensor as stated in the following equation:

,

where C0 is constant. Thermal conductivity is determined by the linear slope of ΔT vs. log(ω) curve. The main advantages of the 3ω-method are minimization of radiation effects and easier acquisition of the temperature dependence of the thermal conductivity than in the steady-state techniques. Although some expertise in thin film patterning and microlithography is required, this technique is considered as the best pseudo-contact method available. (ch23)

The process was first published by David Cahill and Robert Pohl in the April 1987 issue of the Physical Review in a paper titled "Thermal Conductivity of Amorphous Solids above the Plateau".

References

Materials testing
Heat conduction
Bucher FS 10 Flugzeugschlepper 78. The Bucher FS 10 Flugzeugschlepper 78 is an aircraft tow vehicle built for the Swiss Air Force by the military vehicle division of Bucher-Guyer AG. Following a restructuring of this division it was sold to Mowag which is now responsible for support.

The Bucher FS 10 Flugzeugschlepper 78 is very compact as it is designed to operate in the Swiss Air Force's aircraft caverns (or underground hangars). It runs on diesel fuel to lower the risk of fire. For precise maneuvering around the caverns, pilot tunnels and shelters it is equipped with special downward-shining floor lighting headlights to help the driver to follow floor markings. It is also used to provide a power supply to aircraft without an Auxiliary power unit. It is used as well as tractors for about 1-4 engine start units or for ad hoc transport of mechanics and tools (e.g. spare wheel and jack by a flat tire of a landed aircraft). JuAir at Dübendorf Air Base is the only civil user of this aircraft tug type. The aircraft tractors are equipped with four quick couplings as standard. This allows them to be loaded with a crane, in a short time, on every flatbed truck of the Swiss military. The Bucher FS 10 Flugzeugschlepper 78 are street-legal, but with their 80 km range and permitted maximum speed of 25 km/h, however, are not independently suitable for ad-hoc transfers. An ad-hoc capability was achieved with the 4 crane couplings. Such ad-hoc transfers were part of the concept of the Swiss Air Force in the Cold War. It was anticipated to use various motorway sections of the Motorways of Switzerland as air force bases. This was also done several times in exercises. In these exercises the Bucher FS 10 Flugzeugschlepper 78 was involved. For example, the "U TAUTO" exercise on March 24, 1982, the Bucher FS 10 Flugzeugschlepper 78 were stationed at the Rest area "Windrose" near Münsingen. JuAir at Dübendorf AFB is the only civil user of this aircraft tug type.

Specifications
 Drive axle rear differential lock
 Drum brakes on all wheels
 Tubeless tires 
 Wheelbase 
 Track 
 Turning radius 
 Ground clearance

References 

Operations Manual Bucher aircraft tractor Kp20FlApt13
 Schweizerisches Militärmuseum Full
 Military vehicles database: Bucher FS 10 - Official Swiss Armed Forces website

External links 
 Bucher FS 10 - www.militaerfahrzeuge.ch; Swiss Military Vehicles unofficial website

Aviation ground support equipment
Vehicles of Switzerland
Jane's ATF: Advanced Tactical Fighters. Jane's ATF: Advanced Tactical Fighters is a 1996 combat flight simulator developed and published by Electronic Arts for DOS. It is the first entry in the Jane's Combat Simulations franchise. An expansion pack, NATO Fighters, was released in 1996, and a compilation package for Microsoft Windows was released in 1997 titled Advanced Tactical Fighters Gold.

Content from the game would be combined into a unified interface with Jane's US Navy Fighters 97 for re-release as Jane's Fighters Anthology in 1997.

Gameplay
Jane's ATF uses the same engine and menus as the 1994 game U.S. Navy Fighters, with updated aircraft and terrain geometry. The base game includes two campaigns, one set in Egypt in 1998 and the other Russia in 2002, as well as single missions, a mission creator, and multiplayer functionality.

The game's flyable planes lean heavily on aircraft that were new or still under development at the time of the game's release, including the F-117 Nighthawk (Stealth Fighter), F-22 Raptor, X-29 FSW, XF-31 EFM, X-32 ASTOVL, B-2 Spirit, and Rafale C.

The NATO Fighters expansion adds a campaign in the Baltic and four new planes: F-16 Fighting Falcon, Saab Gripen, EuroFighter 2000, and Su-35.

Reception

In Computer Gaming World, Denny Atkin praised the game and its features, but complained for lacking multiplayer mode. Steve Wartofsky called ATF an "evolutionary rather than revolutionary step" for Jane's Combat Simulations, but argued that it set the standard for its genre. While he found its graphics to be a "mixed bag", he enjoyed the game overall, and highlighted its encyclopedia as its best feature.

Writing for PC Gamer US, Dan Bennett called ATF as a solid, good-looking sim, but found the game to be overly difficult.

Next Generation reviewed the PC version of the game positively and recommended it for flight sim fans.

In 1996, the editors of Computer Gaming World nominated ATF for their "Simulation of the Year" award, which ultimately went to EF2000. They wrote that ATF "makes up for its aging engine by providing the best multiplayer environment of any modern sim". It was also a nominee for the Computer Game Developers Conference's 1996 "Best Simulation Game" Spotlight Award, but lost the prize to MechWarrior 2: Mercenaries.

The expansion, NATO Fighters, received 7.8 out of 10 from T. Liam McDonald of GameSpot who called it "[...] a must, as it expands considerably on the original program and doubles its play life."

References

1996 video games
Combat flight simulators
DOS games
Electronic Arts games
Jane's Combat Simulations
Multiplayer and single-player video games
Video games developed in the United States
Windows games
Orbital Propulsion Centre. The Orbital Propulsion Centre Lampoldshausen (abbreviated LAM), a Division of ArianeGroup, is the European competence centre for development and production of satellite and orbital propulsion systems (spacecraft propulsion). Founded in 1963 by Ludwig Bölkow as a branch of the Bölkow-Entwicklungs-KG, the centre is situated  within the German Aerospace Center (DLR) site at Lampoldshausen, Germany.

Notable milestones 

In 1969 the development, qualification and test of bi-propellant propulsion systems for satellite orbit and attitude control system was started, with first application on the French and German Symphonie (satellite), which was successfully launched from the Kennedy Space Center on December 19, 1974.

2001 the RIT-10 gridded Ion thruster fully recovers the Artemis (satellite) mission from a total loss.

With the maiden flight of the Automated Transfer Vehicle - Jules Verne, launched 9 March 2008, the LAM site demonstrated its orbital propulsion competences within man-rated spacecraft as main sub-contractor for the Propulsion Re-boost SubSystem Assemblies.

Orbital propulsion solutions 

From orbital propulsion to high-performance propulsion systems and equipment, the Lampoldshausen site covers the full range of requirements for satellites and spacecraft. The Orbital Propulsion Centre supplies chemical and electrical orbital propulsion solutions  to all European prime contractors (Airbus, OHB and TAS) and other customers worldwide. Its ability to meet all orbital propulsion requirements is unique.

References 

Spacecraft propulsion
Aerospace companies of Europe
Navigation and Bombing System. The Navigation and Bombing System, or NBS,  was a navigation system used in the Royal Air Force's V-bomber fleet. Primary among its parts was the Navigation and Bombing Computer (NBC), a complex electromechanical computer that combined the functions of dead reckoning navigation calculation with a bombsight calculator to provide outputs that guided the aircraft and automatically dropped the bombs with accuracy on the order of a few hundred metres on missions over thousands of kilometres.

Inputs to the NBS system included late models of the H2S radar, the True Airspeed Unit, a gyrocompass and the Green Satin radar. A Mk 6 radar altimeter was used for accurate height measurement but was not connected to the NBC. These inputs were used to set the Ground Speed Unit, which carried out the navigation calculations, which in turn fed the autopilot system. The NBC did not feed the T4 bombsight computer for visual sighting.

References
 

Mechanical computers
Aerial bombing
Amazon-class frigate (1773). The Amazon-class frigates of 1773, made up of 32-gun fifth rates with a main battery of 12-pounder guns. They were designed by the Surveyor of the Navy, John Williams during his employment by the Admiralty.

The class comprised eighteen ships; Amazon, Ambuscade and Thetis were launched in 1773; the second batch - Cleopatra, Amphion, Orpheus, Juno, Success, Iphigenia, Andromache, Syren, Iris, Greyhound, Meleager, , Solebay, Terpsichore and Blonde - were launched in 1779 to 1787.

Citations

Fifth-rate frigates of the Royal Navy
1773 ships

References
David Applegate. David L. Applegate is an American computer scientist known for his research on the traveling salesperson problem.

Education 
Applegate graduated from the University of Dayton in 1984, and completed his doctorate in 1991 from Carnegie Mellon University, with a dissertation on convex volume approximation supervised by Ravindran Kannan.

Career 
Applegate worked on the faculty at Rice University and at AT&T Labs before joining Google in New York City in 2016. His work on the Concorde TSP Solver, described in a 1998 paper, won the Beale–Orchard-Hays Prize of the Mathematical Optimization Society,
and his book The traveling salesman problem with the same authors won the Frederick W. Lanchester Prize in 2007.
He and Edith Cohen won the IEEE Communications Society's William R. Bennett Prize for a 2006 research paper on robust network routing. Another of his papers, on arithmetic without carrying, won the 2013 George Pólya Award. In 2013, he was named an AT&T Fellow.

With Guy Jacobsen and Daniel Sleator, Applegate was the first to computerize the analysis of the pencil-and-paper game, Sprouts.

Selected publications

References

External links

Year of birth missing (living people)
Living people
American computer scientists
University of Dayton alumni
Carnegie Mellon University alumni
Rice University faculty
Flexblue. Flexblue was a concept of a small nuclear power plant (50 to 250 MWe), measuring a hundred meters long and about 14 meters in diameter. The reactor would be placed several tens of metres underwater, several kilometres off the sea coast. The surrounding sea water would provide the heat sink for the reactor, as well as protection from attack.

It was studied by Naval Group (French industrial group specialised in naval defence and marine renewable energy) from 2008 to around 2016, in partnership with AREVA, the CEA and EDF. The production unit, as it was presented by its promoters, could be used by developing countries and in areas of developed countries that need to compensate for an energy deficit. Another target market for the reactor was medium-sized countries, like Monaco, which may be unsuitable for large nuclear plants.

Proponents of the Flexblue technology point out that this type of reactor would be much less prone to terrorist attacks than terrestrial-based ones. However, nuclear reactor leaks would be much more difficult and costly to resolve underwater. Scholars have pointed out that operating a nuclear reactor underwater would also raise the surrounding water temperature by several degrees and affect the surrounding marine biome.

See also

Related Pages
List of small nuclear reactor designs
Naval Group
Energy policy of the European Union

External links
 Official site of Flexblue Naval Group
 List of Small Nuclear Reactors
 The encyclopedia of Earth - Small nuclear power reactors

References 

Electric power in Europe
Energy in the European Union
Nuclear reactors
Nuclear power reactor types
Puri–Ahmedabad Weekly Express. The 20861 / 20862 Puri–Ahmedabad Weekly Express is an Express train belonging to East Coast Railway zone that runs between  and  in India. It is currently being operated with 18405/18406 train numbers on a weekly basis.

Service

The 18405/Puri–Ahmedabad Express has an average speed of 54 km/h and covers 1995 km in 37h 5m. The 18406/Ahmedabad–Puri Express has an average speed of 52 km/h and covers 1995 km in 38h 10m.

Route & halts

The important halts of the train are:

Coach composition

The train has standard LHB rakes with a max speed of 110 kmph. The train consists of 22 coaches:
 1 AC II Tier
 3 AC III Tier
 9 Sleeper coaches
 1 Pantry car
 6 General Unreserved
 2 End-on Generator

Traction

It is hauled by a Visakhapatnam Loco Shed or Vadodara Loco Shed-based WAP-7 electric locomotive on its entire journey.

Rake sharing 

The train shares its rake with 12887/12888 Puri–Howrah Express.

Direction reversal

The train reverses its direction twice at;
  and
 .

See also 
 Puri railway station
 Ahmedabad Junction railway station
 Puri–Howrah Express

Notes

References

External links 
 18405/Puri–Ahmedabad Express India Rail Info
 18406/Ahmedabad–Puri Express India Rail Info

Rail transport in Puri
Transport in Ahmedabad
Rail transport in Odisha
Rail transport in Chhattisgarh
Rail transport in Maharashtra
Rail transport in Gujarat
Express trains in India
VD-dev. VD-dev (formerly Digital Concept and Velez & Dubail Dev. Team) is a French video game development studio founded in 1990. The studio was closely affiliated with Atari and Ubisoft, working on games commissioned by them before stepping into independent game development.

History 
The studio was founded by the programmer Fernando Velez and the graphic designer Guillaume Dubail, with both working on game design.  After abandoning a shoot 'em up concept in 1989, they developed Jim Power in Mutant Planet under the name Digital Concept. They parted ways between 1992 and 1996 (Guillaume Dubail worked on Jim Power's graphics while Fernando Velez programmed Mr. Nutz and Jurassic Park Part 2: The Chaos Continues for Game Boy). They were credited under their names beginning in 1996, then as Velez & Dubail Dev. Team from 2002 (V-Rally 3) and eventually as VD-dev from 2007. In 2013, they were reunited by Frédéric Zimmer, animation programmer for Ubisoft's Watch Dogs. Fernando Velez died in July 2016; he was 46 years old.

Games developed

References

External links 
 Official Site

Video game development companies
Video game companies of France
Video game companies established in 1990
French companies established in 1990
Patna–Hatia Express. The 18623 / 18624 Patna–Hatia Express is an Express train belonging to South Eastern Railway zone that runs between  and  in India. It is currently being operated with 18623/18624 train numbers on a daily basis.

Service

The 18623/Islampur–Hatia Express has an average speed of  and covers  in 12hr 55min. The 18624/Hatia–Islampur Express has an average speed of  and covers  in 13hr 55min.

Route & Halts 

The All halts of the train are:-

Coach composition

The train has standard LHB rakes with a max speed of . The train consists of 22 coaches :

 1 First AC 
 2 AC II Tier
 7 AC III Tier
 1 AC lll Economy
 7 Sleeper Coaches
 2 General Unreserved
 1 Seating cum Luggage Rake
 1 EOG (End of Generator)

Traction

Both trains are hauled by an Electric Loco Shed, Pt. Deen Dayal Upadhayaya-based WAP-4 and Electric Loco Shed, Gomoh-based WAP-7 electric locomotive from Hatia to Islampur.

Rake sharing

The train shares its rake with 20801/20802 Islampur–New Delhi Magadh Express.

Direction reversal

The train reverses its direction 1 times:

See also 

 Patna Junction railway station
 Hatia railway station
 Patna–Haita Patliputra Express
 Patna–Hatia Super Express
 Islampur–Patna Express

Notes

References

External links 

 18623/Patna–Hatia Express
 18624/Hatia–Patna Express

Transport in Ranchi
Transport in Patna
Express trains in India
Rail transport in Bihar
Rail transport in Jharkhand
Rail transport in West Bengal
Ranchi–Ajmer Garib Nawaz Express. The 18631 / 18632 Ranchi–Ajmer Garib Nawaz Express is an express train belonging to South Eastern Railway zone that runs between  and  in India. It is currently being operated with 18631/18632 train numbers on a weekly basis.

Service

The 18631/Ranchi–Ajmer Garib Nawaz Express has an average speed of 51 km/h and covers 1678 km in 33h 10m. The 18632/Ajmer–Ranchi Garib Nawaz Express has an average speed of 51 km/h and covers 1678 km in 32h 45m.

Coach composition

The train has standard ICF rakes with a max speed of 110 kmph. The train consists of 15 coaches :

 2 AC III Tier
 5 Sleeper coaches
 6 General Unreserved
 2 Seating cum Luggage Rake

See also 

 Ranchi Junction railway station
 Ajmer Junction railway station
 Ajmer–Bangalore City Garib Nawaz Express
 Garib Nawaz Express

Notes

References

External links 

 18632/Ajmer–Ranchi Garib Nawaz Express
 18631/Ranchi–Ajmer Garib Nawaz Express

Transport in Ranchi
Rail transport in Puri
Express trains in India
Rail transport in Rajasthan
Rail transport in Uttar Pradesh
Rail transport in Bihar
Rail transport in Jharkhand
Railway services introduced in 2017
Named passenger trains of India
Memorials to Mu'in al-Din Chishti