omniomni/omni-engineering huggingface dataset:
Ziesite. Ziesite is a copper vanadate mineral with formula: β-Cu2V2O7.  It was discovered in 1980 as monoclinic crystals occurring as volcanic sublimates around fumaroles in the crater of the Izalco Volcano, El Salvador.  It is named after Emanuel George Zies (1883–1981), an American geochemist who studied Izalco in the 1930s.

Closely related is blossite, also a copper vanadate with formula of α-Cu2V2O7.  It forms orthorhombic crystals.  Blossite was also first described for specimens from the Izalco volcano.

Ziesite and blossite are polymorphs, different crystal structure for the same chemical composition and are quite similar in physical properties. 

Associated minerals include stoiberite, shcherbinaite, bannermanite, fingerite, mcbirneyite, blossite, chalcocyanite and chalcanthite.

References

Copper(II) minerals
Vanadate minerals
Monoclinic minerals
Minerals in space group 15
Fokker F.V. The Fokker F.V was a Dutch airliner created by Fokker in the 1920s. The most interesting property of the F.V was that it could be configured either as a biplane or a monoplane, as the lower wing could be removed. It was not a success and only one was built.

Design and development
There are no surviving records of the early thinking of Anthony Fokker that lead to this unusual aircraft, designed by Reinhold Platz. The idea was that the biplane configuration would  be able to lift greater loads because of the greater wing area, whereas the monoplane version would suffer lower drag and be faster. The upper wing was a typical Fokker thick, internally braced design, with ailerons projecting beyond the wingtips, all in the style of the earlier F.III and F.IV aircraft. However, with the F.V it was mounted as a parasol wing, connected to the fuselage by four struts on each side. The biplane conversion was designed to be simple, with the lower wing connected to the upper by simple N type struts, uncomplicated by bracing wires.

Fokker's earlier machines had fabric covered tube steel fuselages, but in the F.V the fabric was replaced by an inner and an outer layer of plywood (both triple-ply) to increase stiffness. The fuselage was flat and deep sided, contributing to yaw stability and in its earliest form no vertical stabiliser was provided, only a rudder. Later the rudder was revised and a fin added.

The engine was a 268 kW (360 hp) Rolls-Royce Eagle water cooled in-line. This drove what was effectively a four-bladed propeller, though it was made by mounting two two-bladed propellers at right angles one behind the other on the single drive shaft. The increased number of blades meant that the diameter, thus tip velocity and noise was less than with a larger two-blade propeller.

The design reflected the realisation that airliners were going to fly further and longer: it had dual controls, toilet and wash facilities and cabin heating. The later was provided by running the engine exhaust pipes horizontally along the aircraft sides above all the cabin windows, where vents allowed the warm air heated by the outside of the exhaust to flow inboard. Seating for eight passengers was provided.

The first flight took place on 7 December 1922 from Schiphol. One characteristic emerged immediately: the plywood panelling of the fuselage made the aircraft vibrate and the cabin extremely noisy. During trials the F.V reportedly flew mostly as a biplane. The sole F.V left the Dutch aircraft register in May 1926, marked "Sold to Austria".

Specifications

References

R. de Leeuw (ed.) Fokker Commercial Aircraft (1994). Fokker publications

F 05
1920s Dutch airliners
Abandoned civil aircraft projects
Aircraft first flown in 1922
Fokker D.XVII. Fokker D.XVII (sometimes written as Fokker D.17), was a 1930s Dutch sesquiplane developed by Fokker. It was the last fabric-covered biplane fighter they developed in a lineage that extended back to the First World War Fokker D.VII.

Design and development

Problems with severe vibration in the Armstrong Siddeley Jaguar radial engine on the Fokker D.XVI resulted in one being converted to use a normally aspirated  Curtiss Conqueror V-1570 V-twelve, becoming the prototype for the D.XVII. 
Production versions were fitted with a  Rolls-Royce Kestrel, while one aircraft was built with a  Lorraine Pétrel and another was built with a  Hispano-Suiza 12Xbrs for comparison purposes. 
Structure was standard for Fokkers throughout the 1920s. The sesquiplane's fuselage was welded steel tube with fabric covering and the wings were made with wood spars and ribs covered with plywood.

Operational history
On 18 January 1935, Lieutenant René Wittert van Hoogland set a Dutch high-altitude record in a Fokker D.XVII of  while using oxygen and high octane fuel.

By May 1939, the aircraft was obsolete and remaining examples were transferred to the LVA Flying School for fighter pilot training however they saw some action during the Battle of the Netherlands, escorting Fokker C.Vs and C.Xs on bombing missions.
When the Netherlands surrendered to the Germans, all surviving aircraft were burnt.

Airspeed Ltd. had a licence to build Fokker aircraft in England and considered making the Fokker D.XVII fighter for Greece under the designation Airspeed AS.17. Greek government interest was constrained by currency concerns. Nevil Shute and a Fokker representative "who was well accustomed to methods of business in the Balkans" spent three weeks in Athens but they did not close the deal.

Operators

Royal Netherlands Air Force
Royal Netherlands East Indies Army - one example

Specifications (Fokker D.XVII)

See also

References

Citations

Bibliography

1930s Dutch fighter aircraft
D 17
Aircraft first flown in 1932
Sesquiplanes
Armstrong Tower. The Armstrong Tower, also known as Alpine Tower, is a distinctive  (425 foot) tall lattice tower featuring three large cross-arms, located atop the Alpine, New Jersey palisades overlooking the Hudson River a few kilometers north of New York City at 40°57'39.0" N and 73°55'21.0" W (40.9607 -73.9225). It is owned by Alpine Tower Company and managed by , both owned by Charles E. Sackermann, Jr.

The tower is the permanent transmitter site for locally based experimental station WA2XMN and Fairleigh Dickinson University's educational FM station WFDU, in additional to numerous directional radio services (including as a cell site). It is clearly visible from across the Hudson River and is used as a Visual flight rules waypoint by aircraft flying within the New York City Special flight rules area.

The tower was originally constructed by inventor Edwin Howard Armstrong in 1938 for developmental activities that led to modern . The original transmissions (W2XMN) occurred at . At the tower base is a building originally used for research by Armstrong, which still has the W2XMN call sign engraved above its main entrance. This building currently houses the Armstrong Field Laboratory, and serves as a museum containing artifacts from the development of FM radio technology.

The structure was also used as a temporary transmitter site for some of New York City's television stations after the collapse of the World Trade Center, including its transmitting antenna, following the September 11, 2001 attacks.

See also
 Lattice tower
 List of towers
 List of famous transmission sites

References

External links
 
 Google Maps view of Armstrong Tower
 Special Event Station W2A - Armstrong Tower - includes museum photos
 Edwin H. Armstrong Plaque at the Armstrong Tower
 FCC History Cards for experimental radio station W2XMN (1936-1950)

Alpine, New Jersey
History of radio in the United States
Towers in New Jersey
Buildings and structures in Bergen County, New Jersey
Towers completed in 1938
1938 establishments in New Jersey
1938 in radio
Temperature jump. The temperature jump method is a technique used in chemical kinetics for the measurement of very rapid reaction rates. It is one of a class of chemical relaxation methods pioneered by the German physical chemist Manfred Eigen in the 1950s. In these methods, a reacting system initially at equilibrium is perturbed rapidly and then observed as it relaxes back to equilibrium. In the case of temperature jump, the perturbation involves rapid heating which changes the value of the equilibrium constant, followed by relaxation to equilibrium at the new temperature.

The heating usually involves discharging of a capacitor (in the kV range) through a small volume (< 1 mL) of a conducting solution containing the molecule/reaction to be studied. In some versions of the apparatus used, the solution is heated instead by the output of a pulsed laser which emits in the near infra-red. When laser heating is employed, the solution need not be conducting. In both cases, the temperature of the solution is caused to rise by a small amount in microseconds (or less in the case of laser heating). This allows the study of the shift in equilibrium of reactions that equilibrate in milliseconds (or microseconds with laser temperature jump), these changes most commonly being observed using absorption spectroscopy or fluorescence spectroscopy. Due to the small volumes involved the temperature of the solution returns to that of its surroundings in minutes.

The fractional extent of the reaction (i.e. the percentage change in concentration of a measurable species) depends on the molar enthalpy change (ΔH°) between the reactants and products and the equilibrium position.  If K is the equilibrium constant and dT is the change in temperature then the enthalpy change is given by the Van 't Hoff equation:

where R is the universal gas constant and T is the absolute temperature. When a single step in a reaction is perturbed in a temperature jump experiment, the reaction follows a single exponential decay function with time constant  equal to a function of the forward (ka) and reverse (kb) rate constants. For the perturbation of a simple equilibrium A <=> B which is first order in both directions, the reciprocal of the time constant equals the sum of the two rate constants 

The two rate constants can be determined from the values of  and the equilibrium constant :, yielding two equations for two unknowns.

In more complex reaction networks, when multiple reaction steps are perturbed, then the reciprocal time constants are given by the eigenvalues of the characteristic rate equations.  The ability to observe intermediate steps in a reaction pathway is one of the attractive features of this technology.

Related chemical relaxation methods include pressure jump, electric field jump and pH jump.

References

Chemical kinetics
1818 in rail transport. 

Events 
 November 13 – Public meeting in Darlington, England, resolves to promote a Stockton and Darlington Railway.

Births 

 April 4 – Robert Pearson Brereton, chief assistant to Isambard Kingdom Brunel who completed many engineering projects after Brunel's death in 1859 (d. 1894)
 July 22 – J. Gregory Smith, president of Northern Pacific Railway 1866–1872, is born (died 1891)

Unknown date births 
 Septimus Norris, steam locomotive designer often credited as the designer of the first 4-6-0 (died 1862)

Deaths

See also 
 Years in rail transport

References
Break junction. A break junction is an electronic device which consists of two metal wires separated by a very thin gap, on the order of the inter-atomic spacing (less than a nanometer). This can be done by physically pulling the wires apart or through chemical etching or electromigration.  As the wire breaks, the separation between the electrodes can be indirectly controlled by monitoring the electrical resistance of the junction.

After the gap is formed, its width can often be controlled by bending the substrate that the metal contacts lie on. The gap can be controlled to a precision of picometers.

A typical conductance versus time trace during the breaking process (conductance is simply current divided by applied voltage bias) shows two regimes. First is a regime where the break junction comprises a quantum point contact. In this regime conductance decreases in steps equal to the conductance quantum  which is expressed through the electron charge (−e) and the Planck constant . The conductance quantum has a value of  siemens, corresponding to a resistance increase of roughly 12.9 kΩ. These step decreases are interpreted as the result of a decrease, as the electrodes are pulled apart, in the number of single-atom-wide metal strands bridging between the two electrodes, each strand having a conductance equal to the quantum of conductance. As the wire is pulled, the neck becomes thinner with fewer atomic strands in it. Each time the neck reconfigures, which happens abruptly, a step-like decrease of the conductance can be observed. This picture inferred from the current measurement has been confirmed by "in-situ" TEM imaging of the breaking process combined with current measurement.

In a second regime, when the wire is pulled further apart, the conductance collapses to values less than the quantum of conductance. This is known as the tunneling regime where electrons tunnel through vacuums between the electrodes.

Use 
Break junctions are used to make electrical contacts to study single molecules.

References

Notes 

Electricity
Molecular electronics
Nanoelectronics
ISBL. ISBL (Information Systems Base Language) is the relational algebra notation that was invented for PRTV, one of the earliest database management systems to implement E.F. Codd's relational model of data.

Example
 OS = ORDERS * SUPPLIERS
 LIST OS: NAME="Brooks" % SNAME, ITEM, PRICE

See also
 IBM Business System 12 - An IBM industrial strength relational DBMS influenced by ISBL.  It was developed for use by customers of IBM's time-sharing service bureaux in various countries in the early 1980s.

External links
 Sample ISBL usage

Query languages
Design marker. In software engineering, a design marker is a technique of documenting design choices in source code using the Marker Interface pattern. Marker interfaces have traditionally been limited to those interfaces intended for explicit, runtime verification (normally via instanceof). A design marker is a marker interface used to document a design choice.  In Java programs the design choice is documented in the marker interface's Javadoc documentation.

Many choices made at software design time cannot be directly expressed in today's implementation languages like C# and Java. These design choices (known by names like Design Pattern, Design Contract, Refactoring, Effective Programming Idioms, Blueprints, etc.) must be implemented via programming and naming conventions, because they go beyond the built-in functionality of production programming languages. The consequences of this limitation conspire over time to erode design investments as well as to promote a false segregation between the designer and implementer mindsets.

Two independent proposals recognize these problems and give the same basic strategies for tackling them. Until now, the budding explicit programming movement has been linked to the use of an experimental Java research tool called ELIDE. The Design Markers technique requires only standard Javadoc-like tools to garner many of the benefits of Explicit Programming.

See also 
 Design Patterns
 Marker interface pattern

External links 
 Design Markers: Explicit Programming for the rest of us
 Design Markers home page
 Explicit Programming manifesto

Software design
Trifluoroiodomethane. Trifluoroiodomethane, also referred to as trifluoromethyl iodide is a halomethane with the formula CF3I. It is an experimental alternative to Halon 1301 (CBrF3) in unoccupied areas.  It would be used as a gaseous fire suppression flooding agent for in-flight aircraft and electronic equipment fires.

Chemistry
It is used in the rhodium-catalyzed α-trifluoromethylation of α,β-unsaturated ketones.

It can be used as a new generation fire extinguishing agent to replace Halon in fire protection systems. The mechanism of extinguishing fires for CF3I is active and primarily based on interruption of the chain reaction in the combustion area of the flame by so-called "negative" catalytic action. It is also used as an eco-friendly insulation gas to replace  SF6 in electrical power industry.

In the presence of sunlight or at temperatures above 100 °C it can react with water, forming hazardous by-products such as hydrogen fluoride (HF), hydrogen iodide (HI) and carbonyl fluoride (COF2).

Environmental effects
Trifluoroiodomethane contains carbon, fluorine, and iodine atoms. Although iodine is several hundred times more efficient at destroying stratospheric ozone than chlorine, experiments have shown that because the weak C-I bond breaks easily under the influence of water (owing to the electron-attracting fluorine atoms), trifluoroiodomethane has an ozone depleting potential less than one-thousandth that of Halon 1301 (0.008-0.01). Its atmospheric lifetime, at less than 1 month, is less than 1 percent that of Halon 1301, and less even than hydrogen chloride formed from volcanoes.

There is, however, still the problem of the C-F bonds absorbing in the atmospheric window. However, the IPCC has calculated the 100-year global warming potential of trifluoroiodomethane to be 0.4 (i.e., 40% of that of CO2).

References

Further reading

External links
 
Data sheet (in Japanese)
Material Safety Data Sheet CF3I (in English)
CF3I can be used as fire extinguishing agent

Halomethanes
Fire suppression agents
Organoiodides
Ozone-depleting chemical substances
Trifluoromethyl compounds
Stefano Nolfi. Stefano Nolfi (born 23 September 1963, Rome) is a director of research of the Institute of Cognitive Sciences and Technologies at the Consiglio Nazionale delle Ricerche and head of the Laboratory of Autonomous Robots and Artificial Life. He is one of the founders of Evolutionary robotics (see his book
published by MIT Press in 2000). Nolfi's research interests include: evolution of communication and language, language and action, adaptive behavior, swarm robotics.

Stefano Nolfi's team at Institute is researching a new approach in developing artificial intelligence in relation to language.

An overview of his work is included in

Nolfi received his laurea (master's) degree in literature and philosophy from the University of Rome La Sapienza in 1986.

References

External links
Stefano Nolfi homepage
Stefano Nolfi's laboratory

Living people
1963 births
Italian roboticists
Italian cognitive scientists
National Research Council (Italy) people
Isodesmic reaction. An isodesmic reaction is a chemical reaction in which the type of chemical bonds broken in the reactant are the same as the type of bonds formed in the reaction product. This type of reaction is often used as a hypothetical reaction in thermochemistry.

An example of an isodesmic reaction is

CH3− +  CH3X  → CH4 + CH2X−   (1)
       
X = F, Cl, Br, I

Equation 1 describes the deprotonation of a methyl halide by a methyl anion. The energy change associated with this exothermic reaction which can be calculated in silico increases going from fluorine to chlorine to bromine and iodine making the CH2I− anion the most stable and least basic of all the halides. Although this reaction is isodesmic the energy change in this example also depends on the difference in bond energy of the C-X bond in the base and conjugate acid. In other cases, the difference may be due to steric strain. This difference is small in fluorine but large in iodine (in favor of the anion) and therefore the energy trend is as described despite the fact that C-F bonds are stronger than C-I bonds.

The related term homodesmotic reaction also takes into account orbital hybridization and in addition there is no change in the number of carbon to hydrogen bonds.

References 
 

Thermochemistry
Computational chemistry
Β-Hexachlorocyclohexane. β-Hexachlorocyclohexane (β-HCH) is an organochloride which is one of the isomers of hexachlorocyclohexane (HCH).  It is a byproduct of the production of the insecticide lindane (γ-HCH).  It is typically constitutes 5–14% of technical-grade lindane,  though it has not been produced or used in the United States since 1985. As of 2009, the Stockholm Convention on Persistent Organic Pollutants classified α-hexachlorocyclohexane and β-HCH as persistent organic pollutants (POPs), due to the chemical's ability to persist in the environment, bioaccumulative, biomagnifying, and long-range transport capacity.

This pesticide was widely used during the 1960s and 1970s, particularly on cotton plants. Although banned as a pesticide more than 30 years ago, traces of beta-HCH can still be found in water and soil. Animal studies show that organochlorine pesticides, including beta-HCH, are neurotoxic, cause oxidative stress, and damage the brain's dopaminergic system. Human studies show that exposure to beta-HCH is linked to Parkinson's and Alzheimer's disease. β-HCH was present in elevated levels in some patients as recently as 2009.
It was manufactured by exhausting chlorination of benzene and for this reason was called erroneously β-BHC.  This synonym still persists.

In March 2005, the Italian National Monitoring System on Chemical Residuals in Food of Animal Origin detected levels of the pesticide β-HCH that were 20 times higher than the legal limit of 0.003 mg/kg in bulk milk from a dairy farm in the Sacco River valley. β-HCH, a lindane isomer and possible human carcinogen, was subsequently found in milk from several neighboring farms. A study was therefore undertaken to evaluate the extent and risk factors for contamination.

See also
α-Hexachlorocyclohexane

References

External links
beta-Hexachlorocyclohexane (beta-HCH) - Integrated Risk Information System – US EPA
Cyclohexane, 1,2,3,4,5,6-hexachloro-, (1α,2β,3α,4β,5α,6β)- – NIST

Organochlorides
Persistent organic pollutants under the Stockholm Convention
Persistent organic pollutants under the Convention on Long-Range Transboundary Air Pollution
Electric knife. An electric carving knife or electric knife is an electrical kitchen device used for slicing foods. The device consists of two serrated blades that are clipped together. When the appliance is switched on, the blades continuously move lengthways to provide the sawing action. They were popular in the United Kingdom in the 1970s.

Invention
The invention of the electric knife is usually attributed to Jerome L. Murray, but there are other claimants, such as Clem E. Kosterman, who filed a patent in 1939.

Electric knives can be corded or cordless.

Other uses
They are also sometimes used for other purposes, including sculpting polyurethane foam rubber, cutting wood, cutting metal, and other solid or semi-solid substances and materials.

Popular culture
In the 1981 horror film Possession, the character of Anna cuts her neck with an electric knife.
In the 1986 horror film Maximum Overdrive, an electric knife turns itself on and cuts waitress Wanda June.
In the third-season Simpsons episode "Dog of Death", Homer attempts to use an electric knife to carve a Thanksgiving turkey at the table, sending pieces of it flying at other family members.
In Stephen King's 1987 novel Misery, Annie Wilkes slices off Paul Sheldon's thumb with an electric knife.

In the 1975 musical horror comedy film The Rocky Horror Picture Show, an electric knife is used by Frank N. Furter to slice Meatloaf.

See also
 Reciprocating saw

References

Kitchen knives
Food preparation appliances
20th-century inventions
American inventions