omniomni/omni-engineering huggingface dataset:
Mentat (disambiguation). A mentat is a profession in the fictional Dune universe created by Frank Herbert.

Mentat may also refer to:

Mentat (computing), a C++ macro-dataflow extension
Mentat (company), a software company acquired by Packeteer in 2004
Mentat (software), preprocessor and postprocessor of MSC Marc software finite element analyses
Mentats, fictional drugs in the Fallout video game series
The Mentat, a school for mental arts in the 1995 science fiction novel The Search for Snout
Space segment. The space segment of an artificial satellite system is one of its three operational components (the others being the user and ground segments). It comprises the satellite or satellite constellation and the uplink and downlink satellite links.

The overall design of the payload, satellite, ground segment, and end-to-end system is a complex task. Satellite communications payload design must be properly coupled with the capabilities and interaction with the spacecraft bus that provides power, stability and environmental support to the payload.

Telecommunications satellites
Geostationary Earth orbit (GEO) supports businesses in satellite television and radio broadcasting, as well as data and mobile communications. The medium Earth orbit (MEO) and low Earth orbit (LEO) configurations can also be used for various applications.

A communications satellite is composed of a communications payload (repeater and antenna) and supporting spacecraft bus (including solar arrays and batteries, attitude and orbit control systems, structure and thermal control system), and is placed in orbit by a launch vehicle. A successful satellite operator needs the right orbital slot or constellation, and satellites that deliver effective power and bandwidth to desirable regions and markets (i.e., those with growing demand for satellite services). , satellite radio serves nearly 32 million subscribers and satellite mobile telephone and data operators offer connectivity throughout the globe. Broadband mobile terminals now provide improved access to the Internet for a range of applications, including videoconferencing.

See also
Comparison of communication satellite operators

References

Satellites
Satellite broadcasting
Spaceflight concepts
De Vlijt, Zuidwolde. De Vlijt (English: The Diligence), formerly known as Hoop van Zegen is a smock mill in Zuidwolde, Drenthe, which has been conserved. The mill was built in 1878 and is listed as a Rijksmonument, number 41099.

History
The first windmill on this site was a post mill that was built in 1731. It burnt down in 1877. To replace it, the drainage mill Zuidplasmolen I was moved to Zoudwolde. It had stood between Moordrecht and Nieuwerkerk aan den IJssel, South Holland. The move was carried out by millwright C H Schiller of Dalfsen, Overijssel. In 1940, the sails were fitted with streamlined leading edges. This was the work of millwright Bisschop of Dalfsen. The mill stopped working after the Second World War, but a restoration was carried out in 1960, being completed in September.

In 1980-81 a further restoration of the mill was carried out. On 1 April 2001, there was a fire at the mill although prompt attendance by the fire brigade saved the mill. The sailstocks were removed on 5 May 2004. As of November 2009, there are no plans to return the mill to working order.

Description

De Wachter is what the Dutch describe as an "achtkante beltmolen". It is a three-storey smock mill on a single-storey brick base. There is no stage, a mound of earth throw up against the base provides access for the sails. The smock and cap are thatched. The mill is winded by a tailpole and winch. The four Common sails had a span of . They had streamlined leading edges. The sails were carried in a cast-iron windshaft which was cast by Enthiizen in 1864. The windshaft also carries the brake wheel which has 71 cogs. This drives the wallower (38 cogs) at the top of the upright shaft. At the bottom of the upright shaft, the great spur wheel, which has 110 cogs, drives the  diameter French Burr stones via a lantern pinion stone nut with 35 staves.

Public access
De Vlijt is open to the public by appointment.

References

Windmills in Drenthe
Smock mills in the Netherlands
Windmills completed in 1878
Rijksmonuments in Drenthe
Octagonal buildings in the Netherlands
De Vlijt, Zuidwolde
Swift heavy ion. Swift heavy ions are the components of a type of particle beam with high enough energy that electronic stopping dominates over nuclear stopping.
They are accelerated in particle accelerators to very high energies, typically in the MeV or GeV range and have sufficient energy and mass to penetrate solids on a straight line. In many solids swift heavy ions release sufficient energy to induce permanently modified cylindrical zones, so-called ion tracks. If the irradiation is carried out in an initially crystalline material, ion tracks consist of an amorphous cylinder. Ion tracks can be produced in many amorphizing materials, but not in pure metals, where the high electronic heat conductivity dissipates away the electronic heating before the ion track has time to form.

Definition 

Heavy ion beams are generally described in terms of their energy in Mega electron volts (MeV) divided by the mass of the atomic nucleus, written "MeV/u".  In order for an ion beam to be considered "swift", the constituent ions should be carbon or heavier, and the energy such that the beam particles have a velocity comparable to the Bohr velocity.

Ion track formation 

The mechanisms by which ion tracks are produced are subject to some debate. They can be considered to produce thermal spikes
in the sense that they lead to strong lattice heating and a transient disordered atom zone.  However, at least the initial stage of the damage might be better understood in terms of a Coulomb explosion mechanism. Regardless of what the heating mechanism is, it is well established that swift heavy ions typically produce a long nearly cylindrical track of damage in insulators, which has been shown to be underdense in the middle, at least in SiO2.

Applications 
Swift heavy ion tracks have several established and potential practical applications. Ion tracks in polymers can be etched to form a nanometer-thin channel through a polymer foil, so called track etch membranes. These are in industrial use.

Irradiation of polyimide resists have potential to be used as templates for nanowire growth.
Tracks can also be used to sputter materials.
They can also be used to elongate nanocrystals embedded in materials. SHI irradiation can also be used for structural modification of nanomaterials.

References 

Condensed matter physics
Radiation effects
Chennai Aero Park. Chennai Aero Park is a proposed aerospace industrial park in Chennai, India. The proposal is supported by the Confederation of Indian Industry, and it is estimated that the park will take up  of land. The Park would attract global players and engage in the design, manufacture and maintenance of all types of aircraft for both civil and military programmes, including training and education.

With the objective of creating an integrated ecosystem for Aerospace Industry development covering design, engineering, manufacturing, servicing and maintenance of aircraft for civil and defence sector in Tamil Nadu, TIDCO is establishing an Aerospace components’ manufacturing park for aerospace industry in Sriperumbudhur (Chennai) in an area of around 250 acres( expandable to 700 acres). The developed plots in sizes of 1 acre, 2 acres, 5 acres, 10 acres, etc in the park will be offered to the aerospace companies. This park will have the following facilities.

1. Metal/composite manufacturing facilities
2. Technology and IT services
3. Avionics
4. Assembly facilities and maintenance facilities
5. Training and R&D

The park will have developed industrial plot in the utilities like power and water and facilitate the building of communication, connectivity and social infrastructures to suit to specific needs of the park. The road connectivity will be developed to the aerospace Park.

List of Companies that have been allotted land:

 SOSHER Dronecrafts (OPC) Pvt. Ltd.
 Bhastrik Mechanical Labs Pvt. Ltd.
 Balaa Works
 Balaa HAR Conn Aerospace Services Pvt. Ltd.
 Metallic Bellows (India) Pvt. Ltd.
 Metalscan Inspection Services
 Intigle Technologies India Private Limited
 Despat Pvt. Ltd.
 Centroid Design Pvt. Ltd.
 Vinmn Aerospace Pvt. Ltd.
 Techware Systems Pvt. Ltd. (formerly Known as Lab Electronics Pvt. Ltd.)
 Industrial NDT Inspection Co.

See also
 Economy of Chennai

References

External links
 , Official website of Tamil Nadu Industrial Development Corporation Limited, Aero Park
 , Download link about Aerospace Advantages in Tamil Nadu
 , NDA government's MAKE IN INDIA policy for Aviation
 , Indigenization of production for defence sector in India
 , Reference to Defence Offset Requirements in India

Buildings and structures in Chennai
Industrial parks in India
Proposed transport infrastructure in India
Aviation in India
Chalmers Naval Architecture Students' Society. The Chalmers Naval Architecture Students' Society (also known as the Föreningen Chalmers Skeppsbyggare or FCS ) is a naval architecture graduate students group at Chalmers University of Technology, Sweden. The Society was found in 1887 following the establishment of the Naval Architecture and Ocean Engineering Department at the university. Since 1948, Föreningen Chalmers Skeppsbyggare has been a member of the Nordic Technical Universities Shipbuilders Congress (NTHS) which includes Chalmers, Technical University of Denmark, Helsinki University of Technology in Finland, Norwegian University of Science and Technology, and the Royal Institute of Technology in Sweden. Roughly, half of the FCS members are from Sweden while the rest are international students. Some of its members are also current members of the Society of Naval Architects and Marine Engineers. Unlike other student organizations at Chalmers, the society runs as a separate entity from the Chalmers Students' Union.

Organization 
Current students attending the naval architecture program automatically become members of the organization. Countries representing the current FCS include Bangladesh, Canada, China, France, Germany, Iran, South Africa, Turkey, and the United States. Day-to-day activities of FCS are carried out by the board members. The Union board elections are held every year, and about ten to twelve students are selected to run the society. The board is divided into different committees to organize the various activities of the group. These committees or departments span from providing technical assistance in the drafting room to planning extracurricular social events. For example, the fish department of FCS is responsible for taking care of the fish tank located in the basement of the naval architecture building in Campus Lindholmen.

Activities
Each year ten members of FCS represent Chalmers in the Nordic Technical Universities Shipbuilders Congress. Chalmers FCS hosted 2009 62nd annual NTHS congress. 2010 NTHS congress will be held in Finland from 11th to 16 March. Its members participate in other FCS sponsored activities such as the Sunday soccer, beer tasting night, FCS barbecues, and various trips. One of the popular events is participating in the Annual Gothenburg City Half Marathon. During 90s, members of FCS built the Waterbike hydrofoil Af Chapman II and competed in the Human Powered Boats Championships.

References

External links
Shipping and Marine Technology at CTH
Föreningen Chalmers Skeppsbyggare
Human Powered Boats Championships 

Chalmers University of Technology
Marine engineering organizations
Engineering societies based in Sweden
Organizations based in Gothenburg
United Kingdom aircraft test serials. United Kingdom aircraft test serials are used to externally identify aircraft flown within the United Kingdom without a full Certificate of Airworthiness. They can be used for testing experimental and prototype aircraft or modifications, pre-delivery flights for foreign customers and are sometimes referred to as "B" class markings.

1930s
An initial set of markings was introduced in 1929, each company was allocated a letter to which would follow a number, sometimes with a hyphen or a gap between. For example, A was allocated to the Armstrong Whitworth Aircraft and A 1 was used in March 1930 on an Armstrong Whitworth Starling. Sometimes Hawker and Vickers would also add the letters PV to the markings to indicate a private venture (that is a type in development not paid for by the Air Ministry).

1940s

The presentation was changed to look like a military serial for security reasons during the Second World War. For example, the prototype de Havilland Mosquito was allocated test markings E-0234.

1948
Following a change back to the original system in 1946 a new system was introduced on 1 January 1948. Each company was allocated a number which followed the British nationality marking G and then followed by an individual identity number. For example, Blackburn Aeroplane & Motor Company were allocated G-2 and the first allocation G-2-1 was used on a Miles Messenger used as an engine testbed for the Cirrus Bombardier. Companies could allocate and re-use the identities as they liked, some ran in sequence from 1 and others used the aircraft manufacturers serial number as part of the marking, for example G-51-200 was a Britten Norman Islander with a manufacturers serial number of 200. Allocations of codes from defunct companies have been reallocated.

Letter sequence 1929–1947

Numeric sequence since 1948

See also
 British military aircraft designation systems
 List of RAF squadron codes
 Royal Air Force roundels
 United Kingdom aircraft registration
 United Kingdom military aircraft serial numbers

References

Bibliography

Aircraft markings
Aircraft registration
British civil aircraft
Bernard Ireland. Bernard Ireland was a British naval engineer, editor of Jane's and writer on naval matters.

Life
Ireland was educated at the Royal Dockyard School, Portsmouth, and the University of Southampton. 

Ireland worked for the Defence Research Agency in ship research. He wrote or coauthored 47 books, as well as contributing to journals and partworks on subjects related to ships and naval campaigns.

Ireland was married and had two children. He died on 8 February 2019.

Bibliography
Warships of the world: major classes. London: Ian Allan, 1976. 
Warships: from sail to the nuclear age. London: Hamlyn, 1978. 
The rise and fall of the aircraft carrier. London: Marshall Cavendish, 1979. 
Warships of the world: escort vessels. London: Ian Allan, 1979. 
Warships of the world: submarines & fast attack craft. London: Ian Allan, 1980. 
Cruisers. London: Hamlyn, 1981. 
Navies of the West. New York: Hippocrene Books, 1984. 
Warship construction. London: Ian Allan, 1987. 
Sea power 2000. London: Arms and Armour, 1990. 
The War in the Mediterranean 1940-1943. London: Arms and Armour, 1993. 
Jane's Battleships of the 20th Century. New York: HarperCollins, 1996. 
Warships of World War II. Glasgow: HarperCollins, 1996. 
Jane's War at Sea, 1897-1997. With Eric Grove. New York: HarperCollins, 1997. 
Jane's Naval History of WWII. New York: HarperCollins, 1998. 
History of Ships. London: Hamlyn, 1999. 
Naval Warfare in the Age of Sail. London: Ted Smart, 2000. 
War at Sea, 1914-1945. London: Cassell, 2002. 
The battle of the Atlantic. Barnsley: Pen & Sword, 2003. 
Válka ve Středomoří: 1940-1943. Prague: Naše vojsko, 2003. 
The fall of Toulon: the last opportunity to defeat the French Revolution. London: Weidenfeld & Nicolson, 2005. 
The illustrated guide to aircraft carriers of the world. London: Hermes House, 2005. 
Leyte Gulf 1944: the world's greatest sea battle. Oxford: Osprey Publishing, 2006. 
Aircraft Carriers of the World. London: Anness, 2007. 
Vliegdekschepen. With Gerjan van Oosten. Utrecht: Veltman Uitgevers, 2007. 
The world encyclopedia of cruisers. London: Lorenz (Anness), 2008. 
The world encyclopedia of destroyers and frigates. London: Lorenz (Anness), 2008.

References

External links
 Royal Dockyard School, Portsmouth

Year of birth missing
20th-century births
2019 deaths
Alumni of the University of Southampton
British military writers
Jens Bache-Wiig. Jens Bache-Wiig (15 November 1880 – 6 May 1965) was a Norwegian engineer and industrialist.

Early life and education
He was born at Bøn, Eidsvoll to factory owner Hartwig Bache-Wiig (1850–1922) and his wife Amalie Kristine Holt (1851–1940). His father and his brother Carl operated a cellulose factory at Bønsdalen until 1889, when the family moved to Kristiania.

At some point after the 1899 Kristiania housing bubble burst, Bache-Wig moved to Germany to study engineering. He first attended the West Saxon University of Applied Sciences of Zwickau, and then the Karlsruhe Institute of Technology, where he took his final exam in 1902.

Career
In 1906, Bache-Wiig was employed by the Westinghouse Electric Company in Pittsburgh, United States. After that, he was appointed professor in electrical engineering at the newly established Norwegian Institute of Technology, where he stayed until 1916. In 1912–13, he published papers on the calculation of electrical machines with AC and DC generators. In 1916, he became managing director of Elektrisk Bureau, a manufacturer of telecommunication equipment. He left Elektrisk Bureau for Standard Electric – a subsidiary of the International Telephone and Telegraph (ITT) – in 1926. In 1931, he was appointed director-general of ITT's Germany division, and received also the responsibility for the ITT's operations in Eastern Europe. Four years later, he resigned from the position, in protest against the New York head office intervening in his area of responsibility.

During the Quisling regime of German-occupied Norway, Bache-Wiig served in the non-political Administrative Council until September 1940, when it was replaced by the Reichskommissariat Norwegen headed by the Norwegian Nazi Terboven. In this Council, he was the Head of the Ministry of Trade and the Ministry of Provisioning. In 1944, he succeeded Axel Aubert as managing director of Norsk Hydro.

Marriages and death
Bache-Wiig married Tordis Nicolaysen (1885–1934) on 8 December 1906; this marriage ended in divorce. He married Hjørdis Tidemand-Johannessen (1891–??) on 20 June 1939.

He died in Bærum on 6 May 1965, and then was buried at Vår Frelsers gravlund.

References

1880 births
1965 deaths
People from Eidsvoll
Norwegian electrical engineers
Academic staff of the Norwegian Institute of Technology
Burials at the Cemetery of Our Saviour
Fermi–Pustyl'nikov model. The Fermi–Pustyl'nikov model, named after Enrico Fermi and Lev Pustyl'nikov, is a model of the Fermi acceleration mechanism.

A point mass falls with a constant acceleration vertically on the infinitely heavy horizontal wall, which moves vertically in accordance with analytic periodic law in time. The point interacts with the wall by the law of elastic collision.  For this model it was proved that under some general conditions the velocity and energy of the point at the moments of collisions with the wall tend to infinity for an open set of initial data having the infinite Lebesgue measure.  This model was introduced in 1968 in, and studied in, by L. D. Pustyl'nikov in connection with the justification of the Fermi acceleration mechanism.

(See also  and references therein).

References

Dynamical systems
Liquid resistor. A liquid resistor is an electrical resistor in which the resistive element is a solution. Fixed-value liquid resistors are typically used where very high power dissipation is required. They are used in the rotor circuits of large slip ring induction motors  to control starting current, torque and to limit large electrical fault currents (while other protection systems operate to clear or isolate the fault). They typically have electrodes made of welded steel plate (galvanised to reduce corrosion), suspended by insulated connections in a conductive chemical solution held in a tank - which may be open or enclosed. The tank body is normally solidly grounded or earthed. A typical unit can be rated for continuous use, or for short periods when used for current limitation in protection systems.

Liquid neutral earthing resistor

A common use in the electrical power generating and distribution industry is as a fault current limiter in the common neutral leg of large three-phase transformers and generators. In the UK they are known as Liquid Neutral Earthing Resistors (LNERs).

A rating of 0.5 megawatt for 30 seconds would not be unusual to protect the winding of a 660 MW generator. In this application where a neutral leg current flows due to a current imbalance between the generator or transformer windings due to a fault, it is limited in magnitude by the resistor.

A permanently installed current transformer (CT) fixed around the neutral leg feeder to the LNER senses the current. The CT sends a signal current to an external sensing circuit (the protection system) which then sends a signal to the relevant circuit breaker to open and disconnect the supply or isolate the generator (or transformer) from the fault. The ohmic value of the resistor is calculated as a function of the permissible fault current and the system voltage to earth.

Electrolyte in power industry LNERs

The electrolyte is normally sodium carbonate (soda ash) and/or sodium bicarbonate (baking soda). This salt solution is alkaline and electrode corrosion effects on galvanised steel tanks is manageable if re-galvanisation is possible.

The resistance of the bulk electrolyte is a function of temperature and the concentration of the salt governed by the formula:

Rθ = 

where θ is the temperature (in Celsius) and R0 is the standardised or datum calibration temperature.

A specialised technique is required to accurately calibrate an LNER electrolyte bulk resistance value and it is normally carried out by experienced power engineers and technicians. This task must be done off-load at routine intervals (roughly 2–4 years depending on results from routine monitoring) to maintain the resistance value within tolerance and facilitate inspection of the LNER.

See also
 Liquid rheostat

References

Electric power
Resistive components