omniomni/omni-engineering huggingface dataset:
Insulation system. The electrical insulation system for wires used in generators, electric motors, transformers, and other wire-wound electrical components is divided into different classes by temperature and temperature rise. The electrical insulation system is sometimes referred to as insulation class or thermal classification. The different classes are defined by NEMA, Underwriters Laboratories (UL), and IEC standards.

For complete electrically operated appliances, the "insulation system" is the overall design of electrical insulation of the energized components to ensure correct function of the device and protection of the user from electric shock.

Temperature classes

The maximum hot-spot operating temperature is reached by adding the rated ambient temperature of the machine (often 40 °C), a temperature rise, and a 10 °C hot-spot allowance. Electrical machines are usually designed with an average temperature below the rated hot-spot temperature to allow for acceptable life. Insulation does not suddenly fail if the hot-spot temperature is reached, but useful operating life declines rapidly; a rule of thumb is a halving of life for every 10 °C temperature increase. 

Older editions of standards listed materials to be used for the various temperature classes. Modern editions of standards are proscriptive, only indicating that the insulation system must provide acceptable life at the specified temperature rise.

In large machines, different systems may be used according to the predicted temperature rise of the machine; for example, in large hydroelectric generators, stator windings may be Class B but the more difficult to cool rotor winding may be Class F.

Categories of insulation 
In IEC standards, the insulation system is a classification based on the level of electrical shock protection given to a user. Functional insulation is that required to prevent short circuits within the equipment. Basic insulation is any material added to protect a user from accidental contact with energized parts. Supplemental insulation is rated to withstand 1500 volts AC. Double insulation is a design concept where failure of one insulation system will not expose the user to a shock hazard due to the presence of a second independent layer of insulation. Reinforced insulation is a supplemental insulation system that is strong enough to effectively perform as if a double insulation system was present. 
Selection of the insulation system is coordinated with the choice of appliance class.

See also
 Insulator (electricity)
 Electrical insulation paper

References

Further reading
 Greg Stone (ed.), Electrical insulation for rotating machines: design, evaluation, aging, testing, and repair, Wiley-IEEE, 2004 

NEMA standards
Electrical safety
Emil Praeger. Emil H. Praeger (August 2, 1892 – October 16, 1973) was an American architect and civil engineer.

Biography
He was born in 1892.

Praeger graduated from Rensselaer Polytechnic Institute in 1915. He served in the U.S. Navy during World War I, after which he spent time at the architectural office of Bertram Goodhue and the New York City engineering firm Madigan-Hyland.

In 1934, as chief engineer for the City of New York Department of Parks & Recreation, Praeger surveyed all New York City parks. Under director Robert Moses, Praeger created architectural drawings, descriptions, and photographs for every park that the city owned. He also acted as head of the civil engineering department at RPI from 1939 to 1946.

During World War II, Praeger served in the US Navy, and he eventually reached the rank of captain. He developed the original design of the concrete floating breakwater – known as "Phoenix" – for the Invasion of Normandy.

Praeger served as consulting engineer on the White House renovations in 1949.

He died on  October 16, 1973.

Selected work
Henry Hudson Bridge, (chief engineer) New York, 1932
Marine Parkway-Gil Hodges Memorial Bridge, (chief engineer) New York, 1937
Pier 57, New York City, 1952
Arecibo Telescope at the Arecibo Observatory, Puerto Rico, 1952.
Holman Stadium, (chief engineer) Vero Beach, Florida, 1953
Tappan Zee Bridge, New York, 1955
Throg's Neck Bridge, (consulting engineer) New York, 1961
Shea Stadium, Flushing, New York, 1964
Dodger Stadium, Los Angeles, California, 1962

References 

1892 births
1973 deaths
20th-century American architects
Modernist architects from the United States
Rensselaer Polytechnic Institute alumni
Rensselaer Polytechnic Institute faculty
RLU-1 Breezy. The RLU-1 Breezy is a homebuilt aircraft known for its "no cockpit" high wing pusher configuration. It is designed to seat the pilot and passenger with a maximum unobstructed view.

Design and development
Designed and built by Charles Roloff, Robert Liposky and Carl Unger, the original Breezy used a modified set of Piper PA-12 wings. Wings from the  Piper PA-14, Piper PA-18, Piper J-3, Piper J-4, Piper J-5, or Cessna 172 can also be used on the design. It first flew on August 7, 1964.

Operational history

Designer and pilot Carl Unger flew thousands of passengers for free in his Breezy prototype. The aircraft is now part of the EAA AirVenture Museum collection.

At the 2014 EAA AirVenture Oshkosh there was a series of special events to celebrate the 50th anniversary of the design, including a fly-in of Breezys.

Variants
Dawes Breezy
Variant with amphibious floats

Specifications (Breezy)

See also

References

Taylor, John W. R.. Jane's All the World's Aircraft 1982–83. Jane's Publishing Company. London. 1983.

External links

Kit manufacturer catalogue
Air and Space Magazine article

Homebuilt aircraft
Parasol-wing aircraft
Single-engined pusher aircraft
Aircraft first flown in 1964
1960s United States sport aircraft
Aircraft with fixed tricycle landing gear
Aircraft manufactured in the United States
Single-engined piston aircraft
Dallair Aeronautica FR-100 Snap!. The Dallair Aeronautica FR-100 Snap! is a homebuilt aerobatic aircraft that can be certified in multiple categories.

Design and development
The Snap! is imported to the United States and may be certified as an Experimental-Exhibition model, S-LSA, or Experimental LSA.

The Snap! is a single-seat low-wing taildragger. It is rated for 6gs positive and 3 gs negative g-force. The fuselage is constructed of welded steel tubing with a carbon fiber covering. The wings are all-aluminum. The aircraft has inverted fuel and oil systems.

Dallair production ended in 2013 and production was assumed by Tecnam as the Tecnam Snap.

Variants
FR-01
Version for the European market. 
FR-100 Snap!
Version for the US market.

Specifications (FR100 Snap!)

References

External links
FR-01 official website
FR-100 official website

Homebuilt aircraft
United Kingdom National Renewable Energy Action Plan. The United Kingdom National Renewable Energy Action Plan was the National Renewable Energy Action Plan (NREAP) for the United Kingdom in the 2010s. The plan was commissioned by the Directive 2009/28/EC which required Member States of the European Union to notify the European Commission with a road map for achieving legally binding renewable energy targets.

The report described how the United Kingdom planned to achieve its legally binding target of 15 per cent share of energy from renewable sources by 2020.

Background

The history of energy production in the UK had been based on natural resources of fossil fuels; meaning that the UK had not been active in exploitation of renewable resources. Compared to many other EU Member States in the 2010s, the UK started from a very low level of renewable energy consumption.

In 2008, one year before Directive 2009/28/EC, the UK adopted the Climate Change Act 2008, mandating a minimum 80 per cent reduction in greenhouse gas emissions compared with 1990 levels, to be achieved by 2050.

Efforts under the United Kingdom National Renewable Energy Action Plan

The National Renewable Energy Action Plan stated that the United Kingdom aimed to source 30 per cent of electricity used, 12 per cent of heating and 10 per cent of transport energy from renewable sources. In 2013, the Energy Act 2013 set decarbonisation targets for the power sector and in 2015, the UK government announced that all coal-fired power plants without carbon capture technology would be closed by 2025.

By the time of the Brexit referendum in 2016, the UK's Climate Change Committee was reporting that the UK would miss its 2020 targets in the plan; although the government insisted it was on target.

Post Brexit

In 2016, The Guardian newspaper reported that the UK was still required to meet the Plan's commitments, despite the country voting to leave the European Union. However, European think tank Centre for European Policy Studies reported in early 2017 that the UK could revoke its commitments after invoking Article 50 of the EU treaty, and in 2018, the European Commission confirmed that the EU's Renewable Energy Directive would no longer apply to the UK after Brexit was formalized (which happened in 2020).

See also

 Energy in the United Kingdom

References

External links 
 National Renewable Energy Action Plan for the United Kingdom (archived from the original on 22 December 2022)

Energy policy of the United Kingdom
Renewable energy in the United Kingdom
Renewable energy policy
Action plans
EN 1090. The EN 1090 standards are European standards that regulate the fabrication and assembly of steel and aluminium structures and are recognized by the Construction Products Regulation.

EN 1090 comprises three parts:

 EN 1090-1: Requirements for conformity assessment for structural components (CE-Marking)
 EN 1090-2: Technical requirements for the execution of steel structures
 EN 1090-3: Technical requirements for the execution of aluminium structures

EN 1090 replaced the nationally applicable regulations, e.g. in Germany DIN 18800-7 and DIN V 4113-3.

References 

Execution class in EN 1090 certification.

External links 

 List of Harmonized Standards

01090
Structural engineering standards
Structural steel
Raab Krähe. The Raab Krähe () is a West German high-wing, single-seat, pusher configuration motor glider that was designed by Fritz Raab for amateur construction around 1958.

Design and development
Raab designed the Krähe specifically for homebuilders.

The Krähe is constructed from wood, with the fuselage made from a wooden structure covered in doped aircraft fabric. The  span wings are built with a wooden structure and covered in plywood and fabric. The wings feature spoilers and a custom Raab-designed airfoil. The tailplane is braced with four cables to the wing trailing edge. The landing gear is a fixed monowheel.

The motor installation is unconventional for a motorglider in that the engine is mounted in the rear of the cabin area, with the propeller in between the top and bottom tail boom tubes. Motors used are usually of an output of about .

About 30 examples were reported completed by 1974.

Operational history
One Krähe built in Austria by Tasso Proppe and imported to the United States was powered by a  Steyr twin-cylinder, four-stroke engine that produced a cruise speed of  on a fuel burn of  per hour. The aircraft is no longer on the US Federal Aviation Administration registry.

Variants
Krähe
Initial model with monowheel landing gear and propeller in between top and bottom tail boom tubes.
Austria Krähe
Later model with tricycle landing gear and propeller rotating around the upper tail boom tube.

Specifications (Krähe)

See also

References

1950s German sailplanes
Homebuilt aircraft
Glider aircraft
Aircraft first flown in 1958
Krähe
Motor gliders
Single-engined pusher aircraft
Fergie Semple. Brigadier Roderick Ferguson Semple,  (26 January 1922 – 31 July 2003) was a British Army officer who served as Director SAS from 1969 to 1972.

Military career
Educated at Aberdeen Grammar School and the University of Aberdeen, Semple was commissioned into the Royal Engineers in 1942. He served in the Second World War with the 6th Airborne Divisional Engineers creating Glider Landing Zones in the Airborne landings in Normandy in June 1944. He received the MC for this.

Semple commanded 9 Independent Parachute Squadron (RE) from 1957 to 1959. He went on to be chief of staff for 16 Parachute Brigade, before becoming commanding officer of 131 Parachute Engineer Regiment. He was appointed Director of the SAS in 1969 before retiring in 1972.

In retirement, Semple became Director-General of Administration in the Omani Department of Defence and a member of the Sultan's National Defence Council. The Airborne Engineers Association still holds an annual Fergie Semple Golf Competition in his honour.

Family
Semple was married to Olivia; they had no children.

References

1922 births
2003 deaths
People educated at Aberdeen Grammar School
Alumni of the University of Aberdeen
Royal Engineers officers
Members of the Order of the British Empire
Recipients of the Military Cross
Special Air Service officers
British Army personnel of World War II
British Army brigadiers
Design 1st. Design 1st is a multi-disciplinary design consultancy founded in 1996 by Kevin Bailey, and is headquartered in Ottawa, Ontario, Canada. The firm employs fifteen people in Mechanical Engineering and Industrial Design with four offices in Vancouver, Toronto, Montreal and Ottawa. Design 1st assists companies in multiple stages of product development – specializing in mechanical engineering, FEA, human factors, packaging, industrial design and manufacturability.

Design 1st has grown to become Canada's largest product design consultancy. In 2011 Design 1st won the Ottawa Center of Innovation’s (OCRI) Solution of the Year Award in recognition of their work with a variety of Canadian startup and growing technology companies.

Some of Design 1st clients include: We-Vibe, ProDrive Systems, Mytrak, Pliant (recently acquired by SanDisk), Gesturetek, BelAir Networks, Clearford Industries Inc, QNX (acquired by RIM), Stanely Healthcare and March Networks.

References

External links

Engineering companies of Canada
Industrial design
Companies based in Ottawa
Manganese(II) iodide. Manganese(II) iodide is the chemical compound composed of manganese and iodide with the formula MnI2(H2O)n. The tetrahydrate is a pink solid while the anhydrous derivative is beige.  Both forms feature octahedral Mn centers. Unlike MnCl2(H2O)4 and MnBr2(H2O)4 which are cis, MnI2(H2O)4 is trans.

Preparation 
Anhydrous MnI2 is prepared from the elements:

The tetrahydrate can be prepared by treating manganese(II) carbonate with hydriodic acid. The anhydrous form can be produced from it by dehydration in a vacuum.

Properties 
Samples turn brown in air under the influence of light as a result of the oxidation of the iodide ion to iodine. It has a trigonal crystal structure of the cadmium iodide type (polytype 2H) with the space group Pm1 (space group no. 164). It dissolves in water and decomposes. The tetrahydrate has a monoclinic crystal structure with the space group P21/c (No. 14).

Applications 
It is often used in the lighting industry.

References

Manganese(II) compounds
Iodides
Metal halides
Runnymede-class landing craft. The Runnymede-class large landing craft are powered watercraft in the United States Army. They replaced older USN-design landing craft, and are a typical Landing Craft Utility design with a bow ramp and large aft superstructure. They transport rolling and tracked vehicles, containers, and outsized and general cargo from ships offshore to shore, as well as to areas that cannot be reached by oceangoing vessels (coastal, harbor, and intercoastal waterways). It can be self-deployed or transported aboard a float-on/float-off vessel. It is classed for coastal service and one-man engine room operations and does not carry a U.S. Coast Guard COI (certificate of inspection) and is classified under 46 CFR subchapter C-uninspected. The vessel's hull is built to and classed to American Bureau of Shipping (ABS) load line rules, although machinery installations generally met ABS machinery rules when built, the vessels systems are not classed by ABS. The vessel can sustain a crew of 2 warrant officers and 11 enlisted personnel for up to 18 days, and 10,000 miles. This class is also equipped with an aft anchor to assist in retracting from the beach. Several are deployed to Europe and aboard Afloat Prepositioning Ships.

Ships
 USAV Runnymede (LCU 2001)
 USAV Kennesaw Mountain (LCU 2002)
 USAV Macon (LCU 2003)
 USAV Stoney Point (LCU 2004) (formerly Aldie)
 USAV Brandy Station (LCU 2005)
 USAV Bristoe Station (LCU 2006)
 USAV Broad Run (LCU 2007)
 USAV Buena Vista (LCU 2008)
 USAV Calaboza (LCU 2009)
 USAV Cedar Run (LCU 2010)
 USAV Wilson Wharf (LCU 2011) (formerly Chickahominy)
 USAV Chickasaw Bayou (LCU 2012)
 USAV Churubusco (LCU 2013)
 USAV Coamo (LCU 2014)
 USAV Contreras (LCU 2015)
 USAV Corinth (LCU 2016)
 USAV El Caney (LCU 2017)
 USAV Five Forks (LCU 2018)
 USAV Fort Donelson (LCU 2019)
 USAV Fort McHenry (LCU 2020)
 USAV Great Bridge (LCU 2021)
 USAV Chattanooga (LCU 2022) (formerly Harpers Ferry )
 USAV Hobkirk (LCU 2023)
 USAV Hormigueros (LCU 2024)
 USAV Kings Mountain (LCU 2025) (formerly Malvern Hill)
 USAV Matamoros (LCU 2026)
 USAV Vigilant Warrior (LCU 2027) (formerly Mechanicsville)
 USAV Missionary Ridge (LCU 2028)
 USAV Molino Del Rey (LCU 2029)
 USAV Monterrey (LCU 2030)
 USAV New Orleans (LCU 2031)
 USAV Palo Alto (LCU 2032)
 USAV Paulus Hook (LCU 2033)
 USAV Perryville (LCU 2034)
 USAV Port Hudson (LCU 2035)

References

External links
 Guantánamo Bay Sailors Assist Visiting Army Landing Craft
 February 2011 Featured Photos
 U.S. Army Ships – a set on Flickr
 

 
Landing craft
Running survey. A running survey is a rough survey made by a vessel while coasting.  Bearings to landmarks are taken at intervals as the vessel sails offshore, and are used to fix features on the coast and further inland. Intervening coastal detail is sketched in.  

The method was used by James Cook, and subsequently by navigators who sailed under—or were influenced by—him, including George Vancouver, William Bligh and Matthew Flinders.

References

Navigation
Surveying
James Cook
Tribromosilane. Tribromosilane is the chemical compound with the formula HBr3Si.  At high temperatures, it decomposes to produce silicon, and is an alternative to purified trichlorosilane of ultrapure silicon in the semiconductor industry.  

The Schumacher Process of silicon deposition uses tribromosilane gas to produce polysilicon, but it has a number of cost and safety advantages over the Siemens Process to make polysilicon.

It may be prepared by heating crystalline silicon with gaseous hydrogen bromide at high temperature. It spontaneously combusts when exposed to air.

References

Silanes
Bromides
Nonmetal halides
Brochocki BKB-1. The Brochocki BKB-1 was a Canadian mid-wing, single-seat, experimental tailless glider that was designed and constructed by Stefan Brochocki with assistance from Witold Kasper and A. Bodek. The designation indicated the contributions of all three men. The aircraft was intended to study flight above the stall angle.

Design and development
The BKB-1 was constructed in 1959 and built entirely from wood. The  wing was swept, had a 9.5:1 aspect ratio and employed a NACA 8-H-12 airfoil. The aircraft had a very high wing area of  which resulted in a light wing loading of just 3.81 lb/sq ft (18.6 kg/m2).

The prototype BKB-1 was originally registered in Canada as CF-ZDK-X. Later it was moved to the United States, owned by Kasper and registered as N2991G.

As a testbed the aircraft went through several modification states. The modifications included aerodynamic devices to improve aircraft control above the stalling angle. These reduced the stall speed to  and resulted in a 200 ft/min (1.0 m/s) rate of descent while stalled. This allowed stalled landings with no ground roll. As a result of these and other design changes the aircraft was designated as the BKB-1A, the "A" indicating aerobatics. The aircraft was intended to be fully aerobatic, including tumbling maneuvers.

Kasper had a plan to produce the aircraft and the developmental derivative Kasper Bekas, which mount different wings to a common fuselage, as a single kit, with the choice of wings, but it seems none was actually produced.

Operational history
The sole BKB-1A was destroyed on 6 November 1971 near Arlington, Washington, when a pilot conducted unauthorized aerobatics in the aircraft, subjecting it to an estimated negative 30g during a high-speed inverted descent. The 31-year-old commercial pilot, who had a total of 3000 flying hours and five hours on type, was wearing a parachute, but did not bail out and was killed in the accident. The National Transportation Safety Board cited as cause factors that the pilot misjudged the aircraft's speed and overstressed the airframe to failure.

Variants
BKB-1
Early configuration of the aircraft
BKB-1A
Later configuration of the same aircraft with modifications for parachute flight above the stalling angle and also aerobatics.

Specifications (BKB-1)

See also

Notes

References

1950s Canadian sailplanes
Homebuilt aircraft
Tailless aircraft
Aircraft first flown in 1959
Mid-wing aircraft
Fluorocitric acid. Fluorocitric acid is an organic compound with the chemical formula . It is a fluorinated carboxylic acid derived from citric acid by substitution of one methylene hydrogen by a fluorine atom. The appropriate anion is called fluorocitrate. Fluorocitrate is formed in two steps from fluoroacetate. Fluoroacetate is first converted to fluoroacetyl-CoA by acetyl-CoA synthetase in the mitochondria. Then fluoroacetyl-CoA condenses with oxaloacetate to form fluorocitrate. This step is catalyzed by citrate synthase. Flurocitrate is a metabolite of fluoroacetic acid and is very toxic because it is not processable using aconitase in the citrate cycle (where fluorocitrate takes place of citrate as the substrate). The enzyme is inhibited and the cycle stops working.

See also 
 Citric acid
 Fluoroacetic acid
 Citrate cycle

References

External links 
PubChem: Fluorocitrate
Human Metabolome Database (HMDB): Fluorocitric acid  
The Chemical and Biochemical Properties of Fluorocitric Acid Pdf

Tricarboxylic acids
Organofluorides
Fluorohydrins
Respiratory toxins
Aconitase inhibitors
Fluorinated carboxylic acids