omniomni/omni-engineering huggingface dataset:
Beriev MBR-2. The Beriev MBR-2 was a Soviet multi-purpose (including reconnaissance) flying boat which entered service with the Soviet Navy in 1935. Out of 1,365 built, nine were used by foreign countries (including Finland and North Korea). In the Soviet Union, it sometimes carried the nickname of "Kорова" (cow) and "Амбар" (barn).

Design

The MBR-2 was designed by Georgy Mikhailovich Beriev and first flew in 1931, powered by an imported 373 kW (500 hp) BMW VI.Z engine. Production models, which arrived in 1934, used a licence-built version of this engine, the Mikulin M-17 of 508 kW (680 hp), and could be fitted with a fixed wheel or ski undercarriage.

Beriev also designed a commercial airliner derivation, the MP-1, which entered airline service in 1934, and a freighter version, which followed in 1936.

In 1935, an improved version was developed, the MBR-2bis, powered by the Mikulin AM-34N engine, and fitted with an enclosed cockpit, dorsal gun-turret and enlarged vertical tail. In this configuration, the machine remained in production until 1941. As with the MBR-2, the bis spawned a commercial derivative and the MP-1bis entered service in 1937.

Variants
 MBR-2M-17 : Short-range maritime reconnaissance, bombing flying-boat, powered by a 508 kW (680 hp) Mikulin M-17B piston engine.
 MBR-2AM-34 or MBR-2bis : Improved version, powered by a Mikulin AM-34N engine.
 MBR-2M-103 : One MBR-2AM-34 was fitted with the more powerful M-103 engine. One prototype only.
 MP-1 : Civil version of the MBR-2M-17 flying-boat. It could carry six passengers in an enclosed cabin. 
 MP-1bis : Civil version of the MBR-2AM-34 flying-boat.
 MP-1T : Freight transport conversion of MBR-2.

Operators

The Finnish Air Force operated five captured aircraft from 1941.
 
Aeroflot
Soviet Naval Aviation

North Korean Air Force

Specifications (MBR-2 AM-34)

See also

References

Bibliography

External links

 Beriev MBR-2 at aeroflight.co.uk
 Century of Flight
 Beriev MBR-2, TsKB-25 (project and prototype)  at Russian Aviation Museum
 MBR-2 series with M-17 engine  at Russian Aviation Museum
 Beriev MP-1, MP-1bis, MP-1T  (civilian variant) at Russian Aviation Museum

MBR-2
High-wing aircraft
Single-engined pusher aircraft
Flying boats
1930s Soviet military reconnaissance aircraft
Aircraft first flown in 1931
Carbylamine reaction. The carbylamine reaction (also known as the Hoffmann isocyanide synthesis) is the synthesis of an isocyanide by the reaction of a primary amine, chloroform, and base. The conversion involves the intermediacy of dichlorocarbene. 

Illustrative is the synthesis of tert-butyl isocyanide from tert-butylamine in the presence of catalytic amount of the phase transfer catalyst benzyltriethylammonium chloride.
Me3CNH2 + CHCl3 + 3 NaOH → Me3CNC + 3 NaCl + 3 H2O

Similar reactions have been reported for aniline. It is used to prepare secondary amines.

Test for primary amines
As it is only effective for primary amines, the carbylamine reaction can be used as a chemical test for their presence. In this context, the reaction is also known as Saytzeff's isocyanide test. In this reaction, the analyte is heated with alcoholic potassium hydroxide and chloroform. If a primary amine is present, the isocyanide (carbylamine) is formed, as indicated by a foul odour. The carbylamine test does not give a positive reaction with secondary and tertiary amines.

Mechanism
The mechanism involves the addition of amine to dichlorocarbene, a reactive intermediate generated by the dehydrohalogenation of chloroform. Two successive base-mediated dehydrochlorination steps result in formation of the isocyanide.

See also 

 Isodiazomethane
 Carbene

References

Organic reactions
Chemical tests
Huisman–Olff–Fresco models. Huisman–Olff–Fresco models (HOF models) are a hierarchical set of 5 models with increasing complexity, designated for fitting unimodal species response curves on environmental gradient.

A implementation of the model including extension for bimodal distributions exists as an R module downloadable from CRAN.

References

 Oksanen's introduction of HOF models, and software to compute them
 

Ecological theories
Harold Barlow. Harold Everard Monteagle Barlow FRS (15 November 1899 – 20 April 1989) was a British engineer.

He was born in Islington, London, the son of Leonard Barlow, an electrical engineer. He entered University College, London where, apart from the World War II years (which he spent at Royal Aircraft Establishment, Farnborough), he spent most of his working life. He was taught by Ambrose Fleming, who held the Pender Chair there. Barlow went on to succeed Fleming in that chair, and hence also in the post of head of department. Among his students, Barlow supervised Charles Kao, the 2009 Nobel Laureate for Physics, for a doctoral degree.

Honours and awards
In March, 1961 he was elected a Fellow of the Royal Society. His application citation stated that he: " Has made important contributions to the devising of improved measuring techniques at centimetre wavelengths. In particular has developed methods of measuring centimetre-wave power by radiation pressure and by use of the Hall Effect in semi-conductors; has made detailed studies of the conductor loss in wave guides and has added substantially to knowledge on the characteristics of surface waves. His further application of the Hall Effect to power measurement at low frequencies is likely to prove of considerable electrical engineering value. He has published two books on centimetre-wave measurements and some 35 scientific and technical papers". 

Barlow received an Honorary Doctorate from Heriot-Watt University in 1971.

In 1988, Barlow was awarded the Royal Medal of the Royal Society in Engineering category, "In recognition of his distinguished research, particularly on microwaves and waveguides, and of his lasting influence as the founder of an unusually productive research school."

See also
 Leonard Monteagle Barlow, his elder brother.

References

External links

 The Papers of Harold Barlow held at Churchill Archives Centre, Cambridge

1899 births
1989 deaths
People from Islington (district)
Royal Medal winners
Fellows of the Royal Society
Engineers from London
British electrical engineers
People educated at Wallington County Grammar School
Alumni of University College London
Academics of University College London
Mountaineering boot. Mountaineering, expedition or high altitude boots are a type of footwear used in mountain climbing. They are designed specifically for moving over harsh terrain.

Design
Not to be confused with hiking boots, mountaineering boots are usually taller, stiffer, and insulated. The boots can be made of leather, plastic, or modern synthetic materials like Kevlar.
 

The extra height and stiffness of mountaineering boots helps support the climber in steep terrain where flexible boots could cause unsure footing and possibly result in a fall. This extra stiffness is traditionally achieved through the use of a full steel shank, though some manufacturers have begun to use carbon fiber to create the necessary stiffness.     

Mountaineering boots are typically designed to be used with crampons. To achieve compatibility with crampons, welts are moulded into the toe and heel of the boot, providing a platform for the crampon to attach to. The stiffness of the boot enhances the precision of the crampon and allows a climber to pursue steeper and more difficult terrain.

Another important aspect of mountaineering boots is warmth. To prevent frostbite in extreme cold conditions, synthetic insulation is incorporated into the boot. Lighter weight boots are classified as single boots. These single boots are insulated as a single unit with the insulation being permanently attached to the rest of the boot. Double boots, another classification, typically consist of a non-insulated leather or plastic outer shell with a removable insulated liner. The purpose of a double boot is long-term protection from cold weather. If the liner becomes wet, it can be removed from the shell and dried inside a sleeping bag. Since the insulation cannot be removed from single boots, they are not ideally suited for multi-day cold weather excursions.

Other uses

Mountaineering boots are used for ice climbing, mixed (rock & ice) climbing, and crevasse traverse and rescue.  They are not completely stiff like ski boots as they need some degree of flexibility for activities such as hiking and snowshoeing.

The versatility of these boots also makes them popular for other activities. With their durability and extreme-weather adaptability, they are worn by snow-plough drivers, cable car operators, mountain rangers (especially in the winter), rescue paramedics, ski lift operators and snowcat drivers.

Mountaineering boots are generally considered to be too stiff for backpacking on established trails.

In recent years, companies have been making mountaineering boots to be NFPA compliant so they may be used in wildland firefighting.

References

Mountaineering Boots - Spadout

Boots
Mountaineering equipment
Lead(IV) acetate. Lead(IV) acetate or lead tetraacetate is an metalorganic compound with chemical formula . It is a colorless solid that is soluble in nonpolar, organic solvents, indicating that it is not a salt. It is degraded by moisture and is typically stored with additional acetic acid. The compound is used in organic synthesis.

Structure
In the solid state the lead(IV) centers are coordinated by four acetate ions, which are bidentate, each coordinating via two oxygen atoms. The lead atom is 8 coordinate and the O atoms form a flattened trigonal dodecahedron.

Preparation
It is typically prepared by treating of red lead with acetic acid and acetic anhydride (), which absorbs water. The net reaction is shown:

The remaining lead(II) acetate can be partially oxidized to the tetraacetate by Cl2, with a PbCl2 by-product:

Reagent in organic chemistry
Lead tetraacetate is a strong oxidizing agent, a source of acetyloxy groups, and a general reagent for the preparation of organolead compounds. Some of its many uses in organic chemistry:
Acetoxylation of benzylic, allylic, and α-oxygen ether C−H bonds, for example the conversion of dioxane to 2-acetoxy-1,4-dioxane 
 An alternative reagent to bromine in Hofmann rearrangement 
 Dehydrogenation of hydrazones and hydrazines, for example that of hexafluoroacetone hydrazone to bis(trifluoromethyl)diazomethane
 Cleavage of α-hydroxy acids or 1,2-diols to their corresponding aldehydes or ketones, often replacing ozonolysis; for instance, the oxidation of di-n-butyl -tartrate to  n-butyl glyoxylate.
 Reaction with alkenes to form γ-lactones
 Oxidation of alcohols carrying a δ-proton to cyclic ethers.
 Oxidative cleavage of certain allyl alcohols in conjunction with ozone:
 Transformation of 1,2-dicarboxylic acids or cyclic anhydrides to alkenes

 Conversion of acetophenones to phenyl acetic acids
 Decarboxylation of carboxylic acids to alkyl halides in the Kochi reaction

Safety
Lead(IV) acetate is toxic. It is a neurotoxin. It affects the gum tissue, central nervous system, kidneys, blood, and reproductive system.

References

Lead(IV) compounds
Oxidizing agents
Acetates
Michael Loam. Michael Loam (1 November 1797 – 14 July 1871) was an English engineer who introduced the first man engine (a device to carry men up and down the shaft of a mine) into the UK.

In 1834, concerned for the health of miners and for the loss in profits incurred by their long, slow climbs by ladders, the Royal Cornwall Polytechnic Society announced a prize for the design of a better system of transporting miners in and out of the deep mines in the county. Michael Loam won this prize in 1841 for his man engine, despite evidence that it was already in use in the Hartz Mountains in Germany.

Inspired by the German designs and constructed of a series of moving platforms, the first man engine was installed in 1842 at Tresavean Mine—one of the deepest in Cornwall at the time. Its adoption was encouraged by the mine's owner, John Rogers.

Loam was trained as an engineer at Wheal Abraham by Arthur Woolf. He remained active in the metal mining and smelting industries in Cornwall and is noted as an investor in the Tamar Tin Smelting Company in 1863.

References

External links

Portrait of Michael Loam, at the Science Museum

1797 births
1871 deaths
Inventors from Cornwall
Engineers from Cornwall
English mining engineers
People from Ludgvan, Cornwall
David Engelke. David Engelke is an American entrepreneur who purchased audio manufacturing company Solid State Logic in cooperation with musician Peter Gabriel in 2005. The imaging, editing and analysis technologies he developed have earned him and his companies three EMMY Awards from the National Academy of Television Arts and Sciences and an OSCAR from the Academy of Motion Picture Arts And Sciences and a technical GRAMMY award from the Recording Academy.

References 

Living people
American businesspeople
Year of birth missing (living people)
Aircar. Aircar may refer to:

 Compressed-air car
 Flying car
 Klein Vision AirCar, a flying car designed by Štefan Klein
 Curtiss-Wright Model 2500 Aircar
 AirCars, a 1997 video game developed by MidNite Entertainment Group Inc.

See also
 Aerocar (disambiguation)
 Flying car (disambiguation)
 Skycar (disambiguation)
SimGear. SimGear is a group of libraries, which provide capabilities useful for simulations, visualizations, and even games building.

SimGear is a relatively new project, and while quite a bit of code has been written in conjunction with the  FlightGear project, the final interface and arrangements are still evolving.

All the SimGear code is designed to be portable across a wide variety of platforms and compilers. Originally, it has been developed in support of the FlightGear project, but as development moved forward, it has become useful for other types of applications as well.

SimGear is free software, licensed under the terms of the GNU LGPL.

External links
 official website
 Documentation
 

Computer libraries
Free simulation software
Video game development software
Lenoir cycle. The Lenoir cycle is an idealized thermodynamic cycle often used to model a pulse jet engine.  It is based on the operation of an engine patented by Jean Joseph Etienne Lenoir in 1860.  This engine is often thought of as the first commercially produced internal combustion engine.  The absence of any compression process in the design leads to lower thermal efficiency than the more well known Otto cycle and Diesel cycle.

The cycle
In the cycle, an ideal gas undergoes
1–2: Constant volume (isochoric) heat addition;
2–3: Isentropic expansion;
3–1: Constant pressure (isobaric) heat rejection.

The expansion process is isentropic and hence involves no heat interaction. Energy is absorbed as heat during the isochoric heating and rejected as work during the isentropic expansion.
Waste heat is rejected during the isobaric cooling which consumes some work.

Constant volume heat addition (1–2)
In the ideal gas version of the traditional Lenoir cycle, the first stage (1–2) involves the addition of heat in a constant volume manner.  This results in the following for the first law of thermodynamics:

There is no work during the process because the volume is held constant:

and from the definition of constant volume specific heats for an ideal gas:

Where R is the ideal gas constant and γ is the ratio of specific heats (approximately 287 J/(kg·K) and 1.4 for air respectively).  The pressure after the heat addition can be calculated from the ideal gas law:

Isentropic expansion (2–3)
The second stage (2–3) involves a reversible adiabatic expansion of the fluid back to its original pressure.  It can be determined for an isentropic process that the second law of thermodynamics results in the following:

Where  for this specific cycle.  The first law of thermodynamics results in the following for this expansion process:  because for an adiabatic process:

Constant pressure heat rejection (3–1)
The final stage (3–1) involves a constant pressure heat rejection back to the original state.  From the first law of thermodynamics we find: .

From the definition of work: , we recover the following for the heat rejected during this process: .

As a result, we can determine the heat rejected as follows: .
For an ideal gas, .

Efficiency

The overall efficiency of the cycle is determined by the total work over the heat input, which for a Lenoir cycle equals 

Note that we gain work during the expansion process but lose some during the heat rejection process.
Alternatively, the first law of thermodynamics can be used to put the efficiency in terms of the heat absorbed and heat rejected,

Utilizing that, for the isobaric process, , and for the adiabatic process, , the efficiency can be put in terms of the compression ratio,

where  is defined to be . Comparing this to the Otto cycle's efficiency graphically, it can be seen that the Otto cycle is more efficient at a given compression ratio. Alternatively, using the relationship given by process 2–3, the efficiency can be put in terms of , the pressure ratio,

Cycle diagrams

References

Thermodynamic cycles
Belgian inventions
Mixed/dual cycle. The dual combustion cycle (also known as the mixed cycle, Trinkler cycle, Seiliger cycle or Sabathe cycle) is a thermal cycle that is a combination of the Otto cycle and the Diesel cycle, first introduced by Russian-German engineer Gustav Trinkler, who never claimed to have developed the cycle himself. Heat is added partly at constant volume (isochoric) and partly at constant pressure (isobaric), the significance of which is that more time is available for the fuel to completely combust. Because of lagging characteristics of fuel this cycle is invariably used for Diesel and hot spot ignition engines. It consists of two adiabatic and two constant volume and one constant pressure processes.

The dual cycle consists of following operations:

 Process 1-2: Isentropic compression
 Process 2-3: Addition of heat at constant volume.
 Process 3-4: Addition of heat at constant pressure.
 Process 4-5: Isentropic expansion.
 Process 5-1: Rejection of heat at constant volume.

Bibliography 

Cornel Stan: Alternative Propulsion for Automobiles, Springer, 2016, , p. 48

References 

Thermodynamic cycles
Magnox (alloy). Magnox is an alloy—mainly of magnesium with small amounts of aluminium and other metals—used in cladding unenriched uranium metal fuel with a non-oxidising covering to contain fission products in nuclear reactors.
Magnox is short for Magnesium non-oxidising.
This material has the advantage of a low neutron capture cross section, but has two major disadvantages:
It limits the maximum temperature (to about 415 Celsius), and hence the thermal efficiency, of the plant.
It reacts with water, preventing long-term storage of spent fuel under water in spent fuel pools.

The magnox alloy Al80 has a composition of 0.8% aluminium and 0.004% beryllium.

See also
 Magnox nuclear power reactors.

References

Magnesium alloys
Nuclear materials
Aluminium–magnesium alloys
Aluminium alloys
Howard Johnson (electrical engineer). Howard Johnson is an electrical engineer, known for his consulting work and commonly referenced books on the topic of signal integrity, especially for high speed electronic circuit design. He served as the chief technical editor for Fast Ethernet and Gigabit Ethernet standardisation, and was recognized by the IEEE as an "Outstanding Contributor" to the IEEE P802.3z Gigabit Task Force.

Johnson earned his Bachelor of Science in Electrical Engineering (1978), Masters of Electrical Engineering (1979), and PhD (1982) from Rice University. His dissertation was titled The design of DFT algorithms.

Area of contribution 
Johnson has significantly raised awareness of analog effects at work in high speed digital electronic systems.

In modern digital systems, it is common for digital designs to be subject to analog effects, even if they operate at a relatively low clock frequency.  Circuits operating at lower clock rates can behave as high speed digital systems if there is sufficient high frequency content in the signal edges (when transitioning between digital logic levels) relative to the distance traveled across a printed circuit board.  As a result of improvements in semiconductor process, faster edge rates of even "low technology" electronic components can be sufficient to make the system effectively high speed and thus subject to havoc caused by unanticipated analog effects.

A good example is his illustration of the matrix of rising edges that result from different combinations of skin-effect and dielectric loss which illustrates PCB design problems one encounters at microwave frequencies.

Johnson was also active in the development of two Institute of Electrical and Electronics Engineers (IEEE) standards that govern Ethernet, IEEE 802.3 Fast Ethernet and IEEE 802.3 Gigabit Ethernet.

Books and publications 

Johnson has written three books:
 High-Speed Digital Design: A Handbook of Black Magic (1993), 
 Fast Ethernet: Dawn of a New Network (1995), 
 High-Speed Signal Propagation: Advanced Black Magic (2003), 

Johnson also ran a monthly column at EDN (magazine) entitled Signal Integrity, which was later moved to a  blog format.

He signed off with his last post "Seek inspiration" on 24 June 2013.

References

External links
  
 Signal Consulting Inc. — Howard Johnson's website
 Dr Howard Johnson on The Amp Hour Podcast (10 January 2012)
 Howard Johnson's (former) High Speed Digital Design courses at the University of Oxford

American electrical engineers
Analog electronics engineers
Rice University alumni
Living people
Year of birth missing (living people)
PAR thrust. Power Augmented Ram thrust (or PAR thrust for short) is the use of displaced air in enhancing the air cushion under the wings or body of what is normally a Wing In Ground-effect or WIG craft. The system can also be used in surface effect ships to increase their top speed.

The configuration can use either the exhaust gases from jet engines or propellers slipstream from either the main engines or special assist engines.  This accelerated air is then either ducted, deflected or directed in such a manner that it will pass underneath the wing or body and assist in the creation of an air cushion.  The purpose of using PAR thrust is to allow the craft to take off at lower speeds than those required if the system was not used.

Some craft only use PAR thrust during takeoff; notable examples of this are the KM and Lun Ekranoplanes that situated their jet engines forward of the wing and deflected the thrust downwards under the wing. Once airborne and at a speed where sufficient lift was generated by the wing alone, the deflection could be removed. The KM required 10 turbojets to have enough power to take off, 8 of them operating in PAR mode; once in level flight, the engines could be throttled back extensively or some of them even shut off.

A notable spin-off of this technique was the A-90 Orlyonok ekranoplan, which was powered in flight by a massive Kuznetsov NK-12 turboprop (by far the most powerful ever built), and required two large turbofans embedded in the nose for take-off, whose ducts pointed permanently downwards under the wings to provide PAR thrust. These engines were shut down during flight to reduce fuel consumption.

Some other craft such as Burt Rutan's PARLC, Russian Strizh PE-201, Volga 2, Ivolga and other WIG craft use this system.  Boats that use this system (surface effect ships) require permanent use of PAR thrust in order to achieve enough lift for normal operation.

References

Aerodynamics