omniomni/omni-engineering huggingface dataset:
Speed tape. Speed tape is an aluminium pressure-sensitive tape used to perform minor repairs on aircraft and racing cars. It is used as a temporary repair material until a more permanent repair can be carried out. It has an appearance similar to duct tape, for which it is sometimes mistaken, but its adhesive is capable of sticking on an airplane fuselage or wing at high speeds, hence the name.

Properties
Depending on the adhesive layer used, it can be resistant to water, solvents, and, for brief periods, flames, and will reflect heat and UV light. It is also able to expand and contract through a wide range of temperatures.

Speed tape may be formed of soft aluminium with an adhesive layer, or a multi-layer laminate including aluminium and cloth in addition to an adhesive layer.

Use
Speed tape is sometimes used to protect sealant while curing, or to patch non-critical components of an aircraft. It can also be used for patching bullet damage to combat aircraft. 

Use of speed tape should be authorized by engineering teams, and has to comply with certain requirements. Fines can be levied against airlines that use it to make improper repairs.

See also
 List of adhesive tapes

References

Adhesive tape
Aircraft components
Silnylon. Silnylon, a portmanteau of "silicone" and "nylon", is a synthetic fabric used mainly in lightweight outdoor gear. It is made by impregnating a thin woven nylon fabric with liquid silicone from both sides. This makes it strong for its weight, as the silicone substantially improves the tear strength. It is also highly waterproof, but not breathable. Many colours are available.

It is used in the manufacture of backpacks, tarps and tarp tents, bivy bags, etc., particularly by ultralight backpackers.

Several types of silnylon are produced. The common type is a quiet, silky, very slippery fabric. The variant known as "crisp silnylon" is lighter, but brittle, noisy in movement, and easily torn. Some versions are made from the stronger nylon 66 and are used for applications like parachutes and hot air balloons. Some use a blend of silicone and polyurethane,  partly to reduce the air pollution during manufacture by reducing the aromatic solvents used in the coating process.

Notes

Woven fabrics
Technical fabrics
Mitrionics. Mitrionics was a Swedish company manufacturing softcore reconfigurable processors. It has been mentioned as  one of EETimes "60 Emerging startups".
The company was founded as Flow Computing in 2002 by Stefan Möhl, Pontus Borg, Andreas Rodman and Christian Merheim to commercialize a massively parallel reconfigurable processor implemented on FPGAs. Mitrion-C was then invented and developed by Stefan Möhl and Pontus Borg. It can be described as turning general purpose chips into massive parallel processors that can be used for high performance computing. Mitrionics massively parallel processor is available on Cray, Nallatech, and Silicon Graphics systems.

The Mitrion Platform consists of the Mitrion Virtual Processor and Mitrion Software Development Kit. The SDK includes a parallel C-family language called Mitrion-C used to program the Mitrion Virtual Processor. Since the Mitrion Virtual Processor can be programmed in software, FPGAs become easier to use as computer accelerators than using hardware design tools such as VHDL or Verilog. The Mitrionics technology claims to make supercomputing performance acceleration accessible to an entire new market of scientists and developers previously unable to benefit from it because of high prices, complex design skills needed, and extremely long development times.

The Mitrion Platform was launched in 2005 and has been used by many of the world's leading supercomputing organizations including NCSA, Oak Ridge National Laboratory, George Washington University, McGill University, National Cancer Institute and Konrad-Zuse Institute Berlin.

Mitrionics is headquartered in Lund, Sweden.

References

External links 
 Company website
 Are FPGAs ready for HPC?
 Compiler turns FPGAs into supercomputers
 Saving Supercomputing with FPGAs

Electronic design automation companies
Reconfigurable computing
Induced polarization. Induced polarization (IP) is a geophysical imaging technique used to identify the electrical chargeability of subsurface materials, such as ore.

The polarization effect was originally discovered by Conrad Schlumberger when measuring the resistivity of rock.

The survey method is similar to electrical resistivity tomography (ERT), in that an electric current is transmitted into the subsurface through two electrodes, and voltage is monitored through two other electrodes.

Induced polarization is a geophysical method used extensively in mineral exploration and mining operations. Resistivity and IP methods are often applied on the ground surface using multiple four-electrode sites. In an IP survey (and when making resistivity measurements), capacitive properties of the subsurface materials are determined as well. As a result, IP surveys provide additional information about the spatial variation in lithology and grain-surface chemistry.

The IP survey can be made in time-domain and frequency-domain mode:

In the time-domain induced polarization method, the voltage response is observed as a function of time after the injected current is switched off or on.

In the frequency-domain induced polarization mode, an alternating current is injected into the ground with variable frequencies. Voltage phase-shifts are measured to evaluate the impedance spectrum at different injection frequencies — this is commonly referred to as spectral IP.

The IP method is one of the most widely used techniques in mineral exploration and in the mining industry. Additionally, IP has applications in hydrogeophysical surveying, environmental investigations and geotechnical engineering projects.

Measurement methods

Time domain

Time-domain IP methods measure the resulting voltage following a change in the injected current. The time domain IP potential response can be evaluated by considering the mean value on the resulting voltage, known as integral chargeability or by evaluating the spectral information and considering the shape of the potential response (i.e. describing the response with a Cole-Cole model).

Frequency domain

Frequency-domain IP methods uses alternating currents (AC) to induce electric charges in the subsurface, and the apparent resistivity is measured at different AC frequencies.

See also 
 DC impedance spectroscopy
 AC impedance spectroscopy
 Electrical resistivity measurement of concrete
 Geophysical imaging

References

Further reading

External links

  Example IP equipment and image results

Geophysical imaging
Electrode array. An electrode array is a configuration of electrodes used for measuring either an electric current or voltage. Some electrode arrays can operate in a bidirectional fashion, in that they can also be used to provide a stimulating pattern of electric current or voltage.

Common arrays include:
 Schlumberger (Wenner)
 Wenner alpha
 Wenner beta
 Wenner gamma
 Pole-pole
 Dipole-dipole
 Pole-dipole
 Equatorial dipole-dipole

Resistivity
Resistivity measurement of bulk materials is a frequent application of electrode arrays. The figure shows a Wenner array, one of the possible ways of achieving this. Injecting the current through electrodes separate from those being used for measurement of potential has the advantage of eliminating any inaccuracies caused by the injecting circuit resistance, particularly the contact resistance between the probe and the surface, which can be high. Assuming the material is homogenous, the resistivity in the Wenner array is given by:

where  is the distance between probes.

Electrode arrays are widely used to measure resistivity in geophysics applications. It is also used in the semiconductor industry to measure the bulk resistivity of silicon wafers, which in turn can be taken as a measure of the doping that has been applied to the wafer, before further manufacturing processes are undertaken.

See also
 Four-terminal sensing
 Multielectrode array
 Electrical resistivity measurement of concrete

References

Further reading
 

Geophysical imaging
Classical fluid. Classical fluids are systems of particles which retain a definite volume, and are at sufficiently high temperatures (compared to their Fermi energy) that quantum effects can be neglected. A system of hard spheres, interacting only by hard collisions (e.g., billiards, marbles), is a model classical fluid. Such a system is well described by the Percus–Yevik equation. Common liquids, e.g., liquid air, gasoline etc., are essentially mixtures of classical fluids. Electrolytes, molten salts, salts dissolved in water, are classical charged fluids. A classical fluid when cooled undergoes a freezing transition. On heating it undergoes an evaporation transition and becomes a classical gas that obeys Boltzmann statistics.
 
A system of charged classical particles moving in a uniform positive neutralizing background is known as a one-component plasma (OCP). This is well described by the hyper-netted chain equation (see classical-map hypernetted-chain method or CHNC). An essentially very accurate way of determining the properties of classical fluids is provided by the method of molecular dynamics. An electron gas confined in a metal is not a classical fluid, whereas a very high-temperature plasma of electrons could behave as a classical fluid. Such non-classical Fermi systems, i.e., quantum fluids, can be studied using quantum Monte Carlo methods, Feynman path integral formulation, and approximately via CHNC integral-equation methods.

See also
Bose–Einstein condensate
Fermi liquid
Many-body theory
Quantum fluid

References

Concepts in physics
Drugget. Druggett or drugget is "a coarse woollen fabric felted or woven, self-coloured or printed one side". Jonathan Swift refers to being "in druggets drest, of thirteen pence a yard".

Formerly, a drugget was a sort of cheap stuff, very thin and narrow, usually made of wool, or half wool and half silk or linen; it may have been corded but was usually plain. The term is now applied to a coarse fabric having a cotton warp and a wool filling, used for rugs, tablecloths, etc.

See also 

 Ratteen

Notes

References

External links

Woollen industry
Printed fabrics
Woven fabrics
Waulked textiles
Air pressurized water. Air pressurized water (APW) extinguishers are a type of fire extinguisher that use ordinary water (H2O) to suppress fire. The water is propelled by ordinary air (atmosphere), pressurized in the extinguisher. They are also known by the slang term water can. Although only effective on Class A fires, they have the advantages of being inexpensive to build and maintain, and leaving no special chemical residue when used.

Construction 

A standard APW extinguisher in the United States contains  of water in a stainless steel tank. The water is discharged by means of a  hose, with a smooth-bore nozzle attached to the tip. They will initially produce a  stream of water, with a discharge time of about 50 seconds.

APW extinguishers are easily refilled by unscrewing the top and filling the cylinder with water about three-quarters of the way up. The top is then screwed back on, and the unit is pressurized with an air compressor via the Schrader valve located on the back of the main valve body.

Conversion to foam 
APW extinguishers are commonly converted into makeshift CAFS extinguishers by drilling two  holes in the pickup tube. The unit is then filled with  of water and Class A foam, aqueous film forming foam (AFFF),  film-forming fluoroprotein (FFFP) or commercial detergent is added to the water in a 1% ratio for class A fires and a 3–6% ratio for Class B fires. Typically, the tip of the smooth-bore application nozzle is then cut off to allow the foam to properly expand. Keeping the nozzle will result in wetter foam and longer range. Cutting the nozzle will result in an expanded, dry foam but will lack the range of the standard water nozzle. Water extinguishers can also be fitted with air aspirators when used with foam (commonly used on AFFF and FFFP foam extinguishers) which will result in a more expanded foam but will lack the durability or heat resistance of compressed air foam.

References

Firefighting equipment
Fire suppression
Wildfire suppression
Sikorsky S-75. The Sikorsky S-75 was a proof-of-concept all-composite helicopter. Sikorsky Aircraft used all-composite materials to replace metal to provide greater strength, lighter weight, lower manufacturing costs, and reduce maintenance costs.

Design and development

The Sikorsky S-75 was developed under the US Army's Advanced Composite Airframe Program (ACAP), the goal of which was the development of an all-composite helicopter fuselage, lighter and less costly to build than predominantly metal airframes in support of the Light Helicopter Experimental (LHX) program. In February 1981, contracts were awarded to Sikorsky and Bell Helicopter, with Bell submitting its Model D292. The S-75 flew for the first time in 27 July 1984.

The S-75 mated an entirely new composite airframe with the twin turboshaft engines, transmission, and main and tail rotors of Sikorsky's S-76A civil transport helicopter. The S-75's floors, roof and most exterior surfaces were of more ballistically-resistant Kevlar, while most of the aircraft's basic load-bearing structure was built of graphite or a graphite/epoxy blend. The machine was equipped with specially designed impact-resistant crew and passenger seats and high-strength pneumatic shock absorbers on its fixed tricycle landing gear, in keeping with the Army's requirement that the ACAP aircraft meet or exceed all existing military crashworthiness standards. The aircraft was flown by two pilots, and could carry up to six passengers in the  rear cabin.

Operational history
The S-75 underwent a 50-hour evaluation by the Army, and was found to have exceeded the weight- and cost-saving criteria set in the original ACAP specification. Sikorsky gained a wealth of data on the fabrication and use of composite airframes through building the S-75, and Sikorsky's later designs incorporated many of its features. Testing of the machine continued through April 1985, after which it was withdrawn from service and placed in long-term storage.

Specifications (S-75)

See also

References

External links

 The Sikorsky Legacy S-75 Advanced Composite Airframe Program
 LHX program on globalsecurity.org

S-075
1980s United States helicopters
1980s United States experimental aircraft
Twin-turbine helicopters
Aircraft first flown in 1984
Hollsmidt 222. The Hollsmidt 222 or HT-1 was a Danish light utility amateur aircraft.

Design and development
The plane was designed by engineer Harald Thyregod in 1958 and built by a farmer Arne Hollænder and Aksel Smidt at Hollænder's farm in Aarre. Therefore, it is known as HT-1 for Harald Thyregod or Hollsmidt for two builders. The idea was to create a light, cheap aircraft, fit to homebuilding, with two engines giving more safety. The engines themselves were converted Volkswagen car engines.

Operational history
The plane was first flown by Harald Thyregod on 24 April 1964. It was used by Arne Hollænder and received a registration OY-FAI. At the end of airworthiness (estimated at 300 hours), in 1978 it was donated to Denmark's "flying" Museum (Dansk Veteranflysamling).

Specifications

References
HT-1 at Dansk Veteranflysamling page and in Danish

1960s Danish civil utility aircraft
Low-wing aircraft
Aircraft first flown in 1964
Twin piston-engined tractor aircraft
Apache Cayenne. Apache Cayenne is an open source persistence framework licensed under the Apache License, providing object-relational mapping (ORM) and remoting services. Cayenne binds one or more database schemas directly to Java objects, managing atomic commit and rollbacks, SQL generation, joins, sequences, and more. With Cayenne's Remote Object Persistence, those Java objects can even be persisted out to clients via Web Services. Or, with native XML serialization, objects can be further persisted to non-Java clients—such as an Ajax-capable browser.

Cayenne supports database reverse engineering and generation, as well as a Velocity-based class generation engine. All of these functions can be controlled directly through the CayenneModeler, a fully functional GUI tool. No XML- or annotation-based configuration is required. An entire database schema can be mapped directly to Java objects quickly, all from the comfort of the GUI-based CayenneModeler. These things together make Cayenne interesting for a user who is new to the enterprise world.

Cayenne supports other features, including caching, a complete object query syntax, relationship pre-fetching, on-demand object and relationship faulting, object inheritance, database auto-detection, and generic persisted objects. Most importantly, Cayenne can scale up or down to virtually any project size.

History
Cayenne started as a project run by ObjectStyle and led by Andrus Adamchik. It was released under the Apache license from its first release in July 2002. In early 2006 the project moved from Objectstyle to the Apache Software Foundation and in December 2006 was promoted to be a top level project of Apache.

Notable milestones in Cayenne's history include the release of Apache Cayenne 3.0 in May 2010 and the release of Apache Cayenne 3.1 in the fall of 2014.

See also
Apache OpenJPA

References

External links

Objectstyle
Cayenne article on theserverside

Cayenne
Java (programming language) libraries
Object–relational mapping
ACRV. The acronym ACRV may refer to:

 Crew Return Vehicle (or Assured Crew Return Vehicle)
 Armoured command and reconnaissance vehicle, the NATO name for artillery fire-control derivatives of the Soviet MT-LBu
 Arrhythmogenic cardiomyopathies of the right ventricle ( also known as Arrhythmogenic right ventricular dysplasia)
 The Australian Research Council Centre of Excellence for Robotic Vision, an Australian robotics research group with nodes at Queensland University of Technology, The University of Adelaide, Monash University, and the Australian National University
Miro Technologies. Miro Technologies, Inc. was a privately held company headquartered in La Jolla, California that developed and supplied ground-based Maintenance, Repair and Overhaul (MRO) and supply management software to the Aerospace / Defense (A&D) and commercial MRO sectors.

Miro initially provided an aftermarket logistics application called GOLD to the A&D market in the USA starting in 1981, and subsequently expanded their product line and customer base to serve both A&D and commercial MRO customers in Europe, India, Asia and South America. Miro’s technology has been deployed in combat by the UK Ministry of Defence in both Iraq and Afghanistan over the last decade.

On 25 October 2012, Boeing acquired Miro Technologies. Miro became part of the Global Services & Support business that falls under Boeing Defense, Space & Security, which is a unit of The Boeing Co.

In March 2016, Miro Technologies was merged with its sister company, Tapestry Solutions in San Diego CA, and no longer exists as a separate organization.

Products
 GOLD: Integrated Maintenance & Supply management software designed for Aerospace / Defense market.
 GOLDesp: Java EE compliant ‘Enterprise Service Platform’ based on the functionality of original GOLD application.
 AuRA: Integrated Maintenance & Supply management software designed for commercial MRO market.

External links
 Miro Technologies homepage
 Boeing Acquisition of Miro Technologies
 Tapestry Solutions homepage

Privately held companies based in California
Aerospace companies of the United States
Companies based in San Diego
Firth Helicopter. The Firth Helicopter was a British helicopter of the early 1950s. Designed to exploit new outrigger rotor technology, the helicopter was abandoned during construction.

Design and development
Based on the designs of American engineer Fred Landgraf who established the Landgraf Helicopter Corporation in the early years of the Second World War, The Firth Helicopter was more of a "proof-of-concept" aircraft than a true prototype. Firth Helicopters Ltd. had obtained rights to the Landgraf patents regarding a concept which involved twin outrigger pylons carrying three-bladed rotors fitted with ailerons to change direction.

The design team of Heenan, Winn and Steele, led by Major J.N. Dundas Heenan who had been previously involved in a similarly unorthodox 1948 aircraft project, the Planet Satellite, utilized the fuselage of the second Satellite prototype, registered G-ALXP in 1951. The small, streamlined Satellite monocoque fuselage consisted of panels of an extremely light magnesium-zirconium alloy. The original contours tapered to a butterfly tail that was eliminated and replaced by a single fin to be topped by a tailplane in a "T tail" design; surprisingly, the Satellite fuselage was integrated seamlessly into the new helicopter planform.

The Satellite's four-seat configuration allowed for a larger helicopter than the Landgraf H-2/H-3 series (the H-4 would have been a 5/8 passenger helicopter) which had been the basis of the first Landgraf concept helicopters. The twin non-articulated type rotors were powered by two 145 hp de Havilland Gipsy Majors.

Testing and evaluation
In 1952, Firth Helicopters began the construction of the FH-01/4 (still registered as G-ALXP) at their Thame, UK facilities. Although the majority of the work had been completed, technical problems with excessive weight on the anterior part of the rotors seemed to be unsurmountable given the limited financial resources of the company. Gradually work ground to a halt without final equipment being installed and no hope for a first flight. The Firth FH-01/4 was presented to the College of Aeronautics at Cranfield in 1955.

Specifications (Firth Helicopter)
Heavenly Body
 Length: 26 ft 3 in
 Height: 9 ft 3 in

See also

References
Notes

Bibliography

 Gunston, Bill. Back to the Drawing Board: Aircraft That Flew But Never Took Off. London: Zenith Imprint, 1996. . 
 Middleton, Don. "Heavenly Body". Aeroplane Monthly Vol. 11, No. 10, Issue: no, 128, October 1983.

External links
 Secret projects UK
  Landgraf Helicopters Company

1950s British experimental aircraft
1950s British helicopters
Transverse rotor helicopters
Twin-engined piston helicopters
T-tail aircraft
Unflown aircraft