omniomni/omni-engineering huggingface dataset:
HAL HPT-32 Deepak. The HAL HPT-32 Deepak ("lamp" in Sanskrit) is an Indian prop-driven primary trainer manufactured by Hindustan Aeronautics Limited and are used as a basic trainer aircraft by the Indian Air Force and the Indian Navy. It has two seats in side-by-side configuration.  It's configuration is low-wing, monoplane, single-engine aircraft designed primarily for the training of pilots in basic aerobatics, navigation, and other flying skills. The HPT-32 is equipped with a turboprop engine, offering good fuel efficiency and handling characteristics for new pilots.

However, it faced several challenges during its service. One of the major drawbacks was issues with the engine, leading to several accidents. As a result, the aircraft's service life was cut short, and it was gradually phased out in favor of more modern trainers, such as the HAL HTT-40.

Operational history
The Deepak is used for primary training, observation, liaison and target towing.

When it flies upside-down fuel flows from a collector tank in the fuselage and the inverted flight is limited to 1 min. Deepak has a theoretical glide ratio of 8.5:1. The IAF and HAL are looking into new safety systems such as Ballistic Recovery Systems to enable it to descend safely in the event of an engine failure. On 16 May 2010 the IAF cleared the installation of a parachute recovery system. The HPT-32 aircraft has been replaced by the Pilatus PC-7 Mk II in the IAF, as its workhorse as a Basic Trainer Aircraft (BTA) in 2013.

Accidents

In 17 Deepak crashes so far, 19 pilots have died. The Comptroller and Auditor General (CAG) of India has been reported as saying the aircraft is "technologically outdated and beset by flight safety hazards" when discussing the grounding of the fleet in 2009. HAL HTT-40 is going replace HAL HPT-32 Deepak as primary trainer.

Versions
HPT-32
Basic version, powered byTextron Lycoming EIO-540-D4B5 flat six piston engine
HTT-34
Turboprop version, powered by  Allison 250-B17D engine. First flew on 17 June 1984.

Operators

 Indian Air Force 144 for basic training
 Indian Navy 8  for basic training

Specifications (HPT-32)

See also

Related HAL development:
HAL HTT-40
HAL HUL-26 Pushpak
HAL HT-2

Comparable or Related Basic Trainers:
Pilatus P-3
Beechcraft T-34 Mentor
PAC CT/4 Airtrainer
North American T-28 Trojan

References

Notes

Bibliography

Taylor, M.J.H. (ed,). Brassey's World Aircraft Systems Directory 1999/2000 Edition. London: Brassey's, 1999. .

Deepak
1970s Indian military trainer aircraft
Single-engined tractor aircraft
Low-wing aircraft
Aircraft first flown in 1977
Aircraft with fixed tricycle landing gear
Single-engined piston aircraft
Neiva Universal. The Neiva N621 Universal is a Brazilian propeller-driven basic trainer and ground attack aircraft manufactured by Indústria Aeronáutica Neiva. It is a cantilever, low-wing monoplane of all-metal construction, with retractable undercarriage and side-by-side seating.

Design and development
The Universal was designed in 1963 by Joseph Kovács as a new primary trainer for the Brazilian Air Force, as a replacement for the T-6 Texan and Fokker S-11/S-12 types then in use. The prototype (Registration PP-ZTW) first flew on 29 April 1966. The Brazilian Air Force ordered 150 aircraft as the T-25 Universal, and increased this order in 1978 by an additional 28 aircraft.  A further developed version (designated the YT-25B Universal II) first flew on 22 October 1978, but was not put into production.

The Universal was also adopted as a counter-insurgency aircraft. It was later replaced by the Tucano in both the advanced training and attack roles, but it is still used as a primary and basic trainer at the Academia da Força Aérea Brasileira (Brazilian Air Force Academy).

Ten aircraft were ordered by the Chilean Army. These aircraft were later transferred to the Chilean Air Force. In 1983 five FACh T-25s were donated to the Paraguayan Air Force.

In 2005, the Brazilian Air Force donated six T-25s to the Fuerza Aérea Paraguaya and another six to the Fuerza Aérea Boliviana.

Operators

Bolivian Air Force

Brazilian Air Force

Chilean Air Force
Chilean Army

Paraguayan Air Force

Specifications (Universal)

Notes

References

External links

Brazilian Air Force's website with the description of the type (in Portuguese)

Universal
1960s Brazilian military trainer aircraft
Low-wing aircraft
Single-engined tractor aircraft
Aircraft first flown in 1966
Aircraft with retractable tricycle landing gear
Single-engined piston aircraft
HMAS Whyalla (FCPB 208). HMAS Whyalla (FCPB 208), named for the city of Whyalla, South Australia, was a  of the Royal Australian Navy (RAN).

Design and construction

Starting in the late 1960s, planning began for a new class of patrol boat to replace the , with designs calling for improved seakeeping capability, and updated weapons and equipment. The Fremantles had a full load displacement of , were  long overall, had a beam of , and a maximum draught of . Main propulsion machinery consisted of two MTU series 538 diesel engines, which supplied  to the two propeller shafts. Exhaust was not expelled through a funnel, like most ships, but through vents below the waterline. The patrol boat could reach a maximum speed of , and had a maximum range of  at . The ship's company consisted of 22 personnel. Each patrol boat was armed with a single Bofors 40mm gun as main armament, supplemented by two .50 cal Browning machineguns and an 81 mm mortar, although the mortar was removed from all ships sometime after 1988. The main weapon was originally to be two 30 mm guns on a twin-mount, but the reconditioned Bofors were selected to keep costs down; provision was made to install an updated weapon later in the class' service life, but this did not eventuate.

Whyalla was built by NQEA in Cairns, Queensland. The ship was laid down on 13 July 1980, launched on 22 May 1982, and commissioned on 3 July 1982.

Fate
Whyalla was based at , and was decommissioned on 2 September 2005. The patrol boat was broken up for scrap in Darwin during 2006, at a cost of $450,000 to the Australian government.

Citations

References

 The chapter is available separately as Semaphore, Issue 17, 2005 in PDF and HTML formats.

Fremantle-class patrol boats
Ships built in Queensland
1982 ships
Neiva Regente. Neiva Regente is a Brazilian propeller-driven four-seat light utility aircraft manufactured by Indústria Aeronáutica Neiva.

History
The design was started in 1959 for a four-seat cabin monoplane aircraft with a high wing and fixed undercarriage. The prototype, designated the Neiva Regente 360C, was first flown on 7 September 1961 with a 145 hp (108 kW) Continental O-300 piston engine.

The type was ordered into production by the Brazilian Air Force with a more powerful 180 hp (134 kW) Lycoming O-360-A1D engine. Eighty aircraft were built originally designated the U-42 (later changed to C-42) for the utility role. First delivery occurred in February 1975.
Neiva developed a three-seat air observation post version for the Air Force, designated the Regente 420L. Its tailcone was lowered in order to improve visibility, and it used a more powerful Continental IO-360D 210 hp engine. The aircraft was first flown in January 1967 as the YL-42.  Forty were built for the Brazilian Air Force as the L-42. It had provision to carry light bombs or rockets on underwing hardpoints.

Neiva also developed a four-seat civil version designated the Lanceiro. The prototype (Registered PP-ZAH) first flew in 1970, followed by production aircraft in 1973. The company's subsequent involvement with Embraer resulted in the Lanceiro's program termination.

Variants
Regente 360C – utility version (80 built)
U-42 – military designation of the Regente 360C
C-42 – military designation changed from U-42
Regente 420L – air observation post version (40 built)
L-42 – military designation of the Regente 420L
Lanciero – civil version (2 built)

Operators

Brazilian Air Force

Zimbabwe Air Force

Specifications (C-42)

References

External links

Regente
Single-engined tractor aircraft
High-wing aircraft
1960s Brazilian aircraft
1960s Brazilian military utility aircraft
1960s Brazilian military aircraft
1960s Brazilian civil utility aircraft
Aircraft first flown in 1961
Single-engined piston aircraft
Woodlands Community College. Woodlands Community College is a mixed secondary school located in east Southampton, Hampshire, in the south of England. It was officially opened as a specialist school for science and engineering by MP David Miliband on 26 January 2005.

The last Ofsted inspection was in 2019, when the school was judged as Requiring Improvement. but most recent inspection lead to the rating of Good.

References

External links
 The school's website
 The school on Ofsted's website

Secondary schools in Southampton
Foundation schools in Southampton

Specialist engineering colleges in England
Specialist science colleges in England
Keum-boo. Keum-boo (; also Geumbu, Kum-Boo or Kum-bu—Korean "attached gold") is an ancient Korean gilding technique used to apply thin sheets of gold to silver, to make silver-gilt. Traditionally, this technique is accomplished by first depleting a surface of sterling silver to bring up a thin layer of fine silver. Then 24 carat gold foil is applied with heat and pressure—mechanical gilding—to produce a permanent diffusion bond. 

Pure precious metals such as gold and silver have a very similar atomic structure and therefore have a good potential for bonding. Heating these metals to a temperature between 260–370°C increases the movement of the atoms. When pressure is added, this causes an electron exchange at the surface between the two metals, creating a permanent diffusion bond. This diffusion bond occurs far below the soldering temperature for either metal (Dhein, 2004).

Examples of this technique have probably been observed, but not positively identified on pieces from the second half of the first millennium B.C. and from the early first millennium A.D. (Oddy, 1981).

This technique is used in many cultures, including Chinese, Japanese and in the West to bond gold to other metals, including iron, copper, aluminum, gold alloys, white gold, palladium and platinum. Foil made from gold alloys can be applied to silver and other metals by first depletion gilding the surface of the foil (Lewton-Brain, 1987–1993).

See also
 Art movement
 Creativity techniques
 List of art media
 List of artistic media
 List of art movements
 List of most expensive paintings
 List of most expensive sculptures
 List of art techniques
 List of sculptors

References
Dhein, Christine (2004). "Keum-Boo Pillow Pendant"
Oddy, Andrew (1981). "Gilding Through the Ages"
Lewton-Brain, Charles (1987–1993). "Keum-Boo"
Korean Kum-Boo Metalwork, Traditional Arts Program Notes, 1998, Department of Anthropology, California Academy of Sciences.

Artistic techniques
Gold
Metal plating
Korean art
Artworks in metal
Eskişehir Air Base. Eskişehir Air Base ()  is a military airport in the city of Eskişehir, Turkey.

Military usage
Eskişehir Air Base is home to the 1st Air Wing (Ana Jet Üs or AJÜ) of the 1st Air Force Command (Hava Kuvvet Komutanlığı) of the Turkish Air Force (Türk Hava Kuvvetleri). Other wings of this command are located in Konya (LTAN), Ankara Akıncı (LTAE), Bandırma (LTBG) and Balıkesir (LTBF). The 1st Air Wing operates two squadrons (filo) of F-4E Phantoms from this airbase. These are 111 Filo and 112 Filo. 113 Filo, operating RF-4Es, has been disbanded.

Accidents and incidents
On 1 August 1994, Douglas C-47A 6041 of Turkish Air Force was written off after an accident at Eskişehir Air Base.

See also
 Hasan Polatkan Airport

References

External links

Airports in Turkey
Turkish Air Force bases
ASSET (spacecraft). ASSET, or Aerothermodynamic Elastic Structural Systems Environmental Tests was an experimental US space project involving the testing of an uncrewed sub-scale reentry vehicle.

Development and testing
Begun in 1960, ASSET was originally designed to verify the superalloy heat shield of the X-20 Dyna-Soar prior to full-scale crewed flights. The vehicle's biconic shape and low delta wing were intended to represent Dyna-Soar's forward nose section, where the aerodynamic heating would be the most intense; in excess of an estimated 2200 °C (4000 °F) at the nose cap.

Following the X-20 Dyna-Soar programs' cancellation in December 1963, completed ASSET vehicles were used in reentry heating and structural investigations with hopes that data gathered would be useful for the development of future space vehicles, such as the Space Shuttle.

Flights
Built by McDonnell, each vehicle was launched on a suborbital trajectory from Cape Canaveral's Pad 17B at speeds of up to 6000 m/s before making a water landing in the South Atlantic near Ascension Island. 

Originally, a Scout launch vehicle had been planned for the tests, but this was changed after a large surplus of Thor and Thor-Delta missiles (returned from deployment in the United Kingdom) became available.

Of the six vehicles built, only one was successfully recovered and is currently on display at the National Museum of the United States Air Force in Dayton, Ohio.

Specifications
Manoeuvring controls: Hydrogen-peroxide reaction control thrusters
Maximum Mach no.: M25
Downrange: 
Apogee: 
 Hypersonic L/D ratio: 1:1

Related content

Comparable aircraft

 Molniya BOR-4
 Martin X-23 PRIME

Winged Gemini

In the mid-1960s, McDonnell proposed a variant of the Gemini capsule that retained the original spacecraft's internal subsystems and crew compartment, but dispensed with the tail-first ballistic reentry, parachute recovery and water landing.

Instead, the vehicle would be heavily modified externally into an ASSET-like lifting-reentry configuration. Post-reentry, a pair of stowed swing-wings would be deployed, giving the spacecraft sufficient lift-to-drag ratio to make a piloted glide landing on a concrete runway using a skid-type landing gear (reinstated from the planned, but cancelled paraglider landing system), much like the Space Shuttle.

According to Mark Wade's Encyclopedia Astronautica, the intent seems to have been to field a crewed military spaceplane at a minimal cost following the cancellation of the Dyna-Soar program.

References

Glider aircraft
Lifting bodies
Spaceplanes
1960s United States experimental aircraft
Unmanned aerial vehicles of the United States
McDonnell aircraft
Rear-inflow jet. The rear-inflow jet is a component of bow echoes in a mesoscale convective system that aids in creating a stronger cold pool and downdraft. The jet forms as a response to a convective circulation having upshear tilt and horizontal pressure gradients. The cold pool that comes from the outflow of a storm forms an area of high pressure at the surface. In response to the surface high and warmer temperatures aloft due to convection, a mid-level mesolow forms behind the leading edge of the storm.

With a mid-level area of low pressure, air is drawn in under the trailing stratiform region of precipitation. As air is drawn in on the rear side of the storm, it begins to descend as it approaches the front line of the cells. Before reaching the leading edge, the jet descends to the surface as a strong downdraft, creating straight-line winds.

Any mature mesoscale convective system is capable of developing its own rear-inflow jet, but questions remain as to what influences the strength of the jet. While the diabatic effects of sublimation, melting and evaporation play a role in influencing jet strength, these effects do not account for cases with strong rear-inflow jets. However, the diabatic effects are responsible for the jet subsiding behind the leading edge of the MCS. The sinking of the jet first starts when the mid level inflow goes under the trailing stratiform cloud before descending to the melting layer.

There are other factors that contribute to the strength of any rear inflow jet.  The strength of a rear inflow jet can be greatly increased with induced vortices at the end of the line, called "line-end vortices" or "book-end vortices." These vortices at either end of the line will help reinforce the rear inflow towards the center of the line. The other factor that can help strengthen the jet is an environment in which the large scale flow is feeding/forcing mid-level air into the rear end of the storm.

See also 

 Convective storm detection
 Derecho
 Line echo wave pattern
 Mesovortex

References

Further reading 
 Jorgensen, Murphy and Wakimoto. "Rear Inflow Evolution in a Non-Severe Bow Echo Observed by Airborne Doppler Radar During Bamex." 
 Houze and Smull. "Rear Inflow in Squall Lines with Trailing Stratiform Precipitation" American Meteorological Society, 1987.
 Harder, Jason. "Enhancement of the Downdraft" University of Wisconsin-Madison, 1998.

Severe weather and convection
Radar meteorology
Mesoscale meteorology
Workover. The term workover is used to refer to any kind of oil well intervention involving invasive techniques, such as wireline, coiled tubing or snubbing.  More specifically, a workover refers to the expensive process of pulling and replacing completion or production hardware in order to extend the life of the well.

Reason to perform a workover
Workovers rank among the most complex, difficult and expensive types of well work. They are performed only if the well completion is terminally unsuitable for the job at hand.  The production tubing may have become damaged due to operational factors like corrosion to the point where well integrity is threatened.  Downhole components such as tubing, retrievable downhole safety valves, or electrical submersible pumps may have malfunctioned, needing replacement.

In other circumstances, the reason for a workover may not be that the completion itself is in a bad condition, but that changing reservoir conditions make the former completion unsuitable.  For example, a high productivity well may have been completed with 5½" tubing to allow high flow rates because a narrower tubing would have unnecessarily choked the flow, but declining productivity could lead to stable flow being unsupportable through such a wide bore.

Operation
Before any workover, the well must first be killed. Since workovers are long planned in advance, there would be much time to plan the well kill and so the reverse circulation would be common. The intense nature of this operation often requires no less than the capabilities of a drilling rig.

The workover begins by killing the well then removing the wellhead and possibly the flow line, then installing a B.O.P. commonly known as a blowout preventer, then lifting the tubing hanger from the casing head, thus beginning to pull the completion out of the well. The string will almost always be fixed in place by at least one production packer. If the packer is retrievable it can be released easily enough and pulled out with the completion string. If it is permanent, then it is common to cut the tubing just above it and pull out the upper portion of the string. If necessary, the packer and the tubing left in the well can be milled out, though more commonly, the new completion will make use of it by setting a new packer just above it and running new tubing down to the top of the old one.

Workovers on casing
Although less exposed to wellbore fluids, casing strings too have been known to lose integrity.  On occasion, it may be deemed economical to pull and replace it.  Since casing strings are cemented in place, this is significantly more difficult and expensive than replacing the completion string.  If in some instances the casing string cannot be removed from the well, it may be necessary to sidetrack the offending area and recomplete, which is also an expensive process.  For all but the most productive well, replacing the casing would never be economical.

References

External links
Schlumberger oilfield glossary

Oil wells
Petroleum production
Scope (Irish TV series). SCOPE was a science television series produced in conjunction with Irish broadcaster Raidió Teilifís Éireann (RTÉ). Each show was a 25-minute, fast moving 'MTV’-style programme targeting young people. It aimed to interest young people in science and engineering and to give a wide perspective on the range of careers available in these areas.

The 2007 series was the fourth in successive years and visited a wide range of locations, from Dublin to Las Vegas, Nevada. It covered topics such as ecological footprints, sleep deprivation, gravity and the science of laughter.

SCOPE was an initiative of the Discover Science & Engineering (DSE) awareness programme, which is managed by Forfás on behalf of the Office of Science and Technology at the Department Jobs, Enterprise and Innovation.

External links
 SCOPE at RTÉ Television

2000s Irish television series
Irish children's television shows
RTÉ original programming
Perpetual energy. Perpetual energy may refer to:

 Perpetual motion, the property of an imaginary device that, once started, continues to move forever with no input of external energy
 Renewable energy, energy collected from resources that are naturally replenished on a human timescale
 Perpetual Energy Inc, a Canadian company owned by Clay Riddell
 Perpetual Energies, a 1987 studio album by Ray Buttigieg
 "Perpetual Energy" (Cow and Chicken), an episode of Cow and Chicken

See also
Infinite energy (disambiguation)
Free energy (disambiguation)
Aluminium diboride. Aluminium diboride (AlB2) is a chemical compound made from the metal aluminium and the metalloid boron. It is one of two compounds of aluminium and boron, the other being AlB12, which are both commonly referred to as aluminium boride.  

Structurally the B atoms form graphite-like sheets with Al atoms between them, and this is very similar to the structure of magnesium diboride. Single crystals of AlB2 exhibit metallic conductivity along the axis parallel to the basal hexagonal plane.

Aluminium boride is considered a hazardous substance as it reacts with acids and hydrogen gas to produce toxic gases. For example, it reacts with hydrochloric acid to release borane and aluminium chloride.

The crystal structure of AlB2 is often used as a prototype structure to describe intermetallic compounds. There are a large number of structure types that fall within the AlB2 structural family.

See also
Boride

References

External links
"Boron";

Borides
Aluminium compounds
Aluminium dodecaboride. Aluminium dodecaboride () is a superhard chemical compound with 17% aluminium content by weight.

It is the hardest boride of the aluminium-boron system, which also includes , ,  and AlB.

Properties
There are two crystalline forms, α-, and γ-. Both forms are very similar and consist of a framework with three-dimensional networks of  and  units. The phase β- is now believed to be the ternary boride .

Preparation
The β-form can be prepared by the reaction of boron(III) oxide with sulfur and aluminium, then adding carbon to the mixture.

Uses
The extreme hardness of  makes it a favorable component of PCBN inserts, which are mainly used in cutting and grinding to replace diamond or corundum.

See also
 Boron
 Aluminium boride

Footnotes

External links
"Boron";
"Lightness and hardness"

Borides
Aluminium compounds