omniomni/omni-engineering huggingface dataset:
Cope reaction. The Cope reaction or Cope elimination, developed by Arthur C. Cope, is the elimination reaction of an N-oxide to an alkene and a hydroxylamine.Typically, the amine oxide is prepared from the corresponding amine with a peroxy acid or comparable oxidant.  The actual elimination requires just heat.  
Illustrative is a synthesis of methylenecyclohexane:

Mechanism and related eliminations
The reaction proceeds through the Ei pathway, with an intramolecular, cyclic 5-membered transition state.  Consequently, the elimination product is always syn and rarely occurs with 6-membered rings.  (Rings with 5 or 7 or more members undergo the reaction just fine.)  

This organic reaction is closely related to the Hofmann elimination, but the base is a part of the leaving group.  Sulfoxides can undergo an essentially identical reaction to produce sulfenic acids, which is important in the antioxidant chemistry of garlic and other alliums. Selenoxides likewise undergo selenoxide eliminations.

Reverse reaction
The reverse or retro-Cope elimination has been reported, in which an N,N-disubstituted hydroxylamine reacts with an alkene to form a tertiary N-oxide. The reaction is a form of hydroamination and can be extended to the use of unsubstituted hydroxylamine, in which case oximes are produced.

References

Elimination reactions
Olefination reactions
Name reactions
Optimization problem. In mathematics, engineering, computer science and economics, an optimization problem is the problem of finding the best solution from all feasible solutions.

Optimization problems can be divided into two categories, depending on whether the variables are continuous or discrete: 
 An optimization problem with discrete variables is known as a discrete optimization, in which an object such as an integer, permutation or graph must be found from a countable set. 
 A problem with continuous variables is known as a continuous optimization, in which an optimal value from a continuous function must be found. They can include constrained problems and multimodal problems.

Continuous optimization problem

The standard form of a continuous optimization problem is

where
  is the objective function to be minimized over the -variable vector ,
  are called inequality constraints
  are called equality constraints, and
  and .

If , the problem is an unconstrained optimization problem. By convention, the standard form defines a minimization problem. A maximization problem can be treated by negating the objective function.

Combinatorial optimization problem

Formally, a combinatorial optimization problem  is a quadruple , where
  is a set of instances;
 given an instance ,  is the set of feasible solutions;
 given an instance  and a feasible solution  of ,  denotes the measure of , which is usually a positive real.
  is the goal function, and is either  or .

The goal is then to find for some instance  an optimal solution, that is, a feasible solution  with

For each combinatorial optimization problem, there is a corresponding decision problem that asks whether there is a feasible solution for some particular measure . For example, if there is a graph  which contains vertices  and , an optimization problem might be "find a path from  to  that uses the fewest edges". This problem might have an answer of, say, 4. A corresponding decision problem would be "is there a path from  to  that uses 10 or fewer edges?" This problem can be answered with a simple 'yes' or 'no'.

In the field of approximation algorithms, algorithms are designed to find near-optimal solutions to hard problems. The usual decision version is then an inadequate definition of the problem since it only specifies acceptable solutions. Even though we could introduce suitable decision problems, the problem is more naturally characterized as an optimization problem.

See also

 
 
 
 
 
 
  − the optimum need not be found, just a "good enough" solution.

References

External links

 

Computational problems
Novagen Software. Novagen Software Ltd (commonly referred to as Novagen) was a British software developer which released a number of computer games on a variety of platforms from the mid-1980s to the early 1990s.

The company was set up by Paul Woakes and Bruce Jordan and employed approximately 18 people. In addition to running Novagen, Paul Woakes also developed and programmed the vast majority of the company's products  and the first version of a custom loading scheme that worked ten times faster than Commodore's own, which became Novaload.

Games
  Encounter! (1983) Atari 8-bit, (1984) C64
  Mercenary (1985) Atari 8-bit, C64, C16, Plus/4, ZX Spectrum, Amstrad CPC, Amiga, Atari ST
 Mercenary: The Second City (1986) expansion pack for Mercenary
 Mercenary Compendium Edition (1987) Mercenary + The Second City
  Backlash (1988) Amiga, Atari ST
  Battle Island (1988) C64
  Hell Bent (1989) Amiga, Atari ST
  Damocles: Mercenary II (1990) Amiga, Atari ST
 Damocles: Mission Disk 1 (1991) Amiga, Atari ST
 Damocles: Mission Disk 2 (1991) Amiga, Atari ST
 Damocles Compendium Edition (1991) Damocles + Mission Disk 1 + Mission Disk 2
  Encounter (1991) Amiga, Atari ST
  Mercenary III (1992) Amiga, Atari ST

References

External links
 The Novagen Team

Defunct video game companies of the United Kingdom
Software companies of the United Kingdom
Derwitzer glider. The Derwitzer glider was a glider that was developed by Otto Lilienthal, so named because it was tested near  (nowadays part of Werder (Havel)) in Brandenburg. It first flew in 1891 and became one of the first successful manned aircraft in the world. Lilienthal used it to make flights of up to 25 metres (80 feet).


Specifications

References
 Otto Lilienthal Museum website
 Centennial of Flight website

19th-century German experimental aircraft
Lilienthal aircraft
Glider aircraft
Aircraft first flown in 1891
1891 in Germany
1891 in science
Monoplanes
Martin XB-33 Super Marauder. The Martin XB-33 Super Marauder was a proposed World War II American bomber aircraft. It was designed by the Glenn L. Martin Company as the Martin Model 190 and was a high-altitude derivative of the company's B-26 Marauder. Two different designs were developed, first as a twin-engined aircraft and then as a four-engined aircraft. The four-engined version was ordered by the United States Army Air Forces, but the program was cancelled before any aircraft were built.

Design and development

XB-33
The first version of the B-33 design, the XB-33, was a twin-tailed medium bomber with two Wright R-3350 engines and pressurised crew compartments; its design began in 1940. It would carry around 4,000 lb (1,814 kg) of bombs. Soon after design of the XB-33 began it became clear that a twin-engined aircraft would not achieve the performance requested by the army. The company moved on to developing a larger four-engined design, the XB-33A.

XB-33A
Following the abandonment of the original twin-engined design, the company continued to design a larger four-engined aircraft, and two prototypes were ordered by the USAAF as the XB-33A; its bombload was to have been 12,000 lb (5,443 kg), as much as that of the B-24 Liberator, the heaviest US bomber flown in combat prior to the B-29.

The original XB-33 design was to have been powered by the R-3350, the redesigned XB-33A was to have used Wright R-2600 engines. The main reason for this was the demand for R-3350s for the B-29, one of the most highly valued projects of the Army Air Forces.

On January 17, 1942, the USAAF placed an order for 400 B-33As, to be built at the government-owned plant in Omaha, Nebraska, operated by Martin. On November 25, 1942, the project was cancelled to allow the Omaha plant to concentrate on manufacturing B-29s.

Variants
XB-33
Prototype medium bomber powered by two 1,800 hp (1,343 kW) R-3350 engines, two ordered and cancelled.
XB-33A
Prototype medium bomber powered by four 1,800 hp (1,343 kW) R-2600-15 engines, two ordered and cancelled.
B-33A Super Marauder
Production variant of XB-33A, 400 ordered and cancelled.

Specifications (B-33A, as designed)

See also

References

Notes

Bibliography
 Encyclopedia of American Aircraft
 

1940s United States bomber aircraft
B-33 Super Marauder
Four-engined piston aircraft
Four-engined tractor aircraft
Shoulder-wing aircraft
Twin-tail aircraft
Aircraft with retractable tricycle landing gear
Cancelled military aircraft projects of the United States
Boeing XB-39 Superfortress. The Boeing XB-39 Superfortress was a United States prototype bomber aircraft, a single example of the B-29 Superfortress converted to fly with alternative powerplants. It was intended to demonstrate that the B-29 could still be put into service even if the first choice of engine, the air-cooled Wright R-3350 radial engine, ran into development or production difficulties.

Design and development
Starting life as the first YB-29 delivered to the United States Army Air Forces, it was sent in November 1943 to the Fisher Body Aircraft Development Section of General Motors to be converted to use Allison V-3420-17 liquid-cooled W24 (twin-V12, common crankcase) inline engines. Fisher was chosen for the modification as it was familiar with the engine, as it was to power the P-75 Eagle that they were then developing. Testing on it began in early 1944.

Further development of the engine and the aircraft was delayed by a series of changes in the planned turbosuperchargers, as the originally specified GE Type CM-2 two-stage turbosupercharger became unavailable due to demands on GE's production of its other turbosuperchargers. Other turbosuperchargers were considered, but the result was that the first flights of the XB-39 had to be made without any turbosuperchargers at all.

Operational history

Fisher finally focused again on the B-39. The first flight of the B-39 was made on 9 December 1944 at Cleveland, Ohio. The initial flight tests of the B-39, without turbosuperchargers installed, were impressive. However, the B-39 program was by now seriously delayed, and the flawed R-3350 B-29s had already been rushed into combat in June 1944.

Despite continuing problems with the B-29s, the aircraft was functioning well enough in combat that it no longer made any sense to shift resources in the manufacturing base to a new engine for the B-29 and so the B-39 was not ordered into production.

Specifications (XB-39)

See also

References

Notes

Bibliography

 Jones, Lloyd S. U.S. Bombers, B-1 1928 to B-1 1980s. Fallbrook, California: Aero Publishers, 1962, second edition 1974. .
 Whitney, Daniel. Vee's For Victory!. Atglen, Pennsylvania: Schiffer Military History, 1998.

External links

 XB-39 on USAF Museum site

B-39 Superfortress
Boeing B-39 Superfortress
Four-engined tractor aircraft
XB-39
Mid-wing aircraft
Aircraft first flown in 1944
Four-engined piston aircraft
Aircraft with retractable tricycle landing gear
Lithopone. Lithopone, C.I. Pigment White 5, is a mixture of inorganic compounds, widely used as a white pigment powder.  It is composed of a mixture of barium sulfate and zinc sulfide. These insoluble compounds blend well with organic compounds and confer opacity.  It was made popular by the cheap production costs, greater coverage.  Related white pigments include titanium dioxide, zinc oxide ("zinc white"), zinc sulfide, and white lead.

History 
Lithopone was discovered in the 1870s by DuPont. It was manufactured by Krebs Pigments and Chemical Company and other companies. The material came in different "seals", which varied in the content of zinc sulfide.  Gold seal and Bronze seals contain 40-50% zinc sulfide, offering more hiding power and strength. Although its popularity peaked around 1920, approximately 223,352 tons were produced in 1990.  It is mainly used in paints, putty, and in plastics.

Stability and darkening
Although barium sulfate is almost completely inert, zinc sulfide degrades upon exposure to UV light, leading to darkening of the pigment.  The severity of this UV reaction is dependent on a combination of two factors; how much zinc sulfide makes up the pigments formulation, and its total accumulated UV exposure.  Depending on these factors the pigment itself can vary in shade over time, ranging from pure white all the way to grey or even black.  To suppress this effect, a dopant may be used, such as a small amount of cobalt salts, which would be added to the formulation.  This process creates cobalt-doped zinc sulfide.  The cobalt salts help to stabilize zinc sulfide so it will not have as severe a reaction to UV exposure.

Production 
Lithopone is produced by coprecipitation of barium sulfate and zinc sulfide.  Most commonly coprecipitation is effected by combining equimolar amounts of zinc sulfate and barium sulfide:
 BaS + ZnSO4→ ZnS · BaSO4
This route affords a product that is 29.4 wt % ZnS and 70.6 wt % BaSO4.  Variations exist, for example, more ZnS-rich materials are produced when zinc chloride is added to the mixture of zinc sulfate and barium sulfide.

Barium sulfide is produced by carbothermic reduction of barium sulfate.  Zinc sulfate is obtained from a variety of zinc products, often waste, by treatment with sulfuric acid.

Safety 
Lithopone is rather nontoxic, due to the insolubility of its components. It has been used in medicine as a radiocontrast agent. Lithopone is allowed to be in contact with foodstuffs in the US and Europe.

See also
 List of inorganic pigments

References

Historical references
.
. 

.
.

Barium compounds
Zinc compounds
Sulfides
Sulfates
Inorganic pigments
Radiocontrast agents
École nationale supérieure d'ingénieurs en informatique, automatique, mécanique, énergétique et électronique. The ENSIAME (École Nationale Supérieure d'Ingénieurs en Informatique Automatique Mécanique Énergétique et Électronique) is one of the French "grandes écoles" of Engineering. It is located in the city of Valenciennes, in the north of France.

Born from the merger between the ENSIMEV, the EIGIP and the ISIV, it educates every-year 200 engineers in 3 areas: 

 Mechanics-Energetics
 Computing and Management of Systems
 Mechatronics

It offers additional courses which complement the engineering courses.

 A Master's specialised in Rail and Transport Systems
 A Diploma in Technological Research (D.R.T)

External links 
ENSIAME Homepage
University of Valenciennes
Valenciennes City Web page

Engineering universities and colleges in France
Education in Valenciennes
Grandes écoles
2002 establishments in France
Buildings and structures in Valenciennes
Equivalent airspeed. In aviation, equivalent airspeed (EAS) is calibrated airspeed (CAS) corrected for the compressibility of air at a non-trivial Mach number.  It is also the airspeed at sea level in the International Standard Atmosphere at which the dynamic pressure is the same as the dynamic pressure at the true airspeed (TAS) and altitude at which the aircraft is flying. In low-speed flight, it is the speed which would be shown by an airspeed indicator with zero error. It is useful for predicting aircraft handling, aerodynamic loads, stalling etc.

where  is actual air density and  is standard sea level density (1.225 kg/m3 or 0.00237 slug/ft3).

 is a function of dynamic pressure:

where  is the dynamic pressure 

EAS can also be obtained from the aircraft Mach number and static pressure.

where  is  (the standard speed of sound at 15 °C),  is the Mach number,  is static pressure, and  is standard sea level pressure (1013.25 hPa).

Combining the above with the expression for Mach number gives EAS as a function of impact pressure and static pressure (valid for subsonic flow):

where  is impact pressure.

At standard sea level, EAS is the same as calibrated airspeed (CAS) and true airspeed (TAS). At any other altitude, EAS may be obtained from CAS by correcting for compressibility error.

The following simplified formula allows calculation of CAS from EAS:

where the pressure ratio  and  are airspeeds and can be measured in knots, km/h, mph or any other appropriate unit.

The above formula is accurate within 1% up to Mach 1.2 and useful with acceptable error up to Mach 1.5. The 4th order Mach term can be neglected for speeds below Mach 0.85.

See also 

 Acronyms and abbreviations in avionics
 ICAO recommendations on use of the International System of Units
 Calibrated airspeed
 Flight instruments
 Global Positioning System
 Indicated airspeed
 Position error
 True airspeed

References

Bibliography
 Anderson, John D. (2007), Fundamentals of Aerodynamics, Section 3.4 (4th edition), McGraw-Hill, New York USA. 
 Gracey, William (1980), "Measurement of Aircraft Speed and Altitude"  (11 MB), NASA Reference Publication 1046.

External links
 Equivalent airspeed calculator

Airspeed
Olf (unit). The olf  is a unit used to measure the strength of a pollution source. It was introduced by Danish professor P. Ole Fanger; the name "olf" is derived from the Latin word , meaning "smelled".

One olf is the sensory pollution strength from a standard person defined as an average adult working in an office or similar non-industrial workplace, sedentary and in thermal comfort, with a hygienic standard equivalent of 0.7 baths per day and whose skin has a total area of 1.8 square metres. It was defined to quantify the strength of pollution sources that can be perceived by humans.

The perceived air quality is measured in decipol.

Examples of typical scent emissions

See also 
 Sick building syndrome

References 

 Professor Ole Fanger's page at the Technical University of Denmark, includes curriculum vitae mentioning him proposing the unit called olf. 

Units of measurement
Olfaction
Ugelstad Laboratory. The Ugelstad Laboratory was founded at the Norwegian University of Science and Technology (NTNU), Trondheim, Norway, in January 2002 to commemorate the late Professor John Ugelstad.

The laboratory specialises in surfactant chemistry and its technical applications, emulsions and emulsion technology, preparation of polymers and polymer particles - such as the monosized microbeads - and their technical applications, plasma chemical modification of surfaces and silica-based chemistry.

Applications include crude oil production and processing, wood pulp and paper, biomedicine, catalysis and material science.

The main purpose is to raise the national level of colloidal science.

External links
 Official website

Norwegian University of Science and Technology
Research institutes in Norway
2002 establishments in Norway
Quiescence. Quiescence (/kwiˈɛsəns/) is a state of quietness or inactivity. It may refer to:

 Quiescence search, in game tree searching (adversarial search) in artificial intelligence, a quiescent state is one in which a game is considered stable and unlikely to change drastically the next few plays
 Seed dormancy, a form of delayed seed germination
 Quiescence, a type of dormancy in trees
 Quiescent phase, the first part of the first stage of childbirth
 The G0 phase of a cell in the cell cycle; quiescence is the state of a cell when it is not dividing
 Quiescent current (biasing) in an electronic circuit
 Quiescent consistency is one of the safety properties for concurrent data structures

See also
 Rest (disambiguation)
Aero Bravo 700. The Bravo 700 is a small, two-seat civil utility aircraft manufactured by Aero Bravo in Brazil in both kit and ready-to-fly form. It is a high-wing monoplane of metal construction with fixed tricycle undercarriage and is classed as an ultralight under Brazilian aviation regulations. An agricultural version, the Bravo 700 Agrícola with spraying gear and a chemical tank with a capacity of 140 L (37 US gal) has been developed to flight-testing stage.

Zenith Aircraft considers the Aero Bravo design an unauthorized copy of the Zenith STOL CH 701.

Specifications (Bravo 700)

References

700
High-wing aircraft
Single-engined tractor aircraft
1990s Brazilian civil utility aircraft
Aircraft with fixed tricycle landing gear
Single-engined piston aircraft
Toxicity characteristic leaching procedure. Toxicity characteristic leaching procedure (TCLP) is a soil sample extraction method for chemical analysis employed as an analytical method to simulate leaching through a landfill.  The testing methodology is used to determine if a waste is characteristically hazardous, i.e., classified as one of the "D" listed wastes by the U.S. Environmental Protection Agency (EPA). The extract is analyzed for substances appropriate to the protocol.

Background
In the United States, the Resource Conservation and Recovery Act (RCRA) of 1976 led to establishment of federal standards for the disposal of solid waste and hazardous waste. RCRA requires that industrial wastes and other wastes must be characterized following testing protocols published by EPA. TCLP is one of these tests.

Application of test
The Environmental Compliance Supervisor at a typical municipal landfill (as defined by RCRA Subtitle D) uses TCLP data to determine whether a waste may be accepted into the facility. If TCLP analytical results are below the TCLP D-list maximum contamination levels (MCLs) the waste can be accepted. If they are above these levels the waste must be taken to a hazardous waste disposal facility and the cost of disposal may increase from about $50.00/ton to as much as $1200.00/ton.

As extremely contaminated material is expensive to dispose of, grading is necessary to ensure safe disposal and to avoid paying for disposal of "clean fill."  The TCLP procedure is generally useful for classifying waste material for disposal options.  

Spent abrasive or soil from a construction site usually needs to have a TCLP for lead done to determine where the waste goes next.

Procedure
TCLP comprises four fundamental procedures:
 Sample preparation for leaching
 Sample leaching
 Preparation of leachate for analysis
 Leachate analysis

In the TCLP procedure the pH of the sample material is first established, and then leached with an acetic acid / sodium hydroxide solution at a 1:20 mix of sample to solvent. For example, a TCLP jug may contain 100g of sample and 2000 mL of solution. The leachate mixture is sealed in extraction vessel for general analytes, or possibly pressure sealed as in zero-headspace extractions (ZHE) for volatile organic compounds and tumbled for 18 hours to simulate an extended leaching time in the ground. It is then filtered so that only the solution (not the sample) remains and this is then analyzed.

See also
Landfill gas monitoring

References

 Davis, Sherry (2001). "Regulated Metals: The Rule of 20." Pollution Prevention Institute, Kansas State University.
 Environment, Health and Safety Online. "The EPA TCLP: Toxicity Characteristic Leaching Procedure and Characteristic Wastes (D-codes)." 2008-03-07.

External links
 "TCLP Questions" - EPA

Environmental soil science
Hazardous waste
Landfill
Tress 90. TRESS 90 (1990–1996) was a Norwegian software project meant to be the replacement for INFOTRYGD, a case-worker support system, used by the Norwegian National Insurance Service.

Due to administrative, political, organizational and technical problems, including extreme cost overruns, the project was eventually abandoned with a total pricetag of  ($200m).

It is still the largest IT failure in Norwegian history.

Sources 
 June 1995 Government report on TRESS-90 (in Norwegian)

Government of Norway