omniomni/omni-engineering huggingface dataset:
Tiger-class fast attack craft. The Type 148 Tiger-class fast attack craft  are a group of missile boats built to a Franco-German design and seeing service in the German Navy. The vessels entered service in the 1970s and served into the early 21st century. While they have been mostly retired from German Navy service, many were transferred to other navies and remained in service longer.

Design 

The vessels had been designed by Lürssen of Germany for Israel. They were a modification of the Jaguar-class fast attack craft but armed with the French Exocet missile. They were built mainly in France by Constructions Mécaniques de Normandie in Cherbourg (CMN) for political reasons; twelve were built and completed there, while another eight of the boats were laid down by CMH, but completed by Lürssen.

Their export to Israel was also blocked for political reasons, and the boats were commissioned into the German Navy as the Tiger class. A number of other boats were built by CMN for various navies to the same design, which became known as the La Combattante II type fast attack craft.

Operational history 
The boats were commissioned into the Bundesmarine in the mid-1970s, replacing the Jaguar-class vessels of the 3rd and 5th Squadrons. At first the boats did not receive names, only numbers, but these were introduced later at the insistence of the crews.

The ships served for 30 years, and received major updates in 1982–84 and 1990–92. After decommissioning they were scrapped or sold to different countries. No direct replacements were procured as due to the changed operating conditions the Deutsche Marine has reduced the number of these fast attack boats drastically and procured instead a smaller number of corvettes.

Ship list

See also 
 La Combattante class fast attack craft

References

Notes

Bibliography

External links 
 Schnellboote TIGER-Klase  – Marine (Official homepage of the German Navy) 
 Warships on the Web
 S46 Fuchs 
 S51 Häher 
 S58 Pinguin 

Missile boat classes
Missile boats of Germany
Missile boats of the German Navy
Missile boats of the Chilean Navy
Missile boats of the Egyptian Navy
France–Germany military relations
Fluorene. Fluorene , or 9H-fluorene is an organic compound with the formula (C6H4)2CH2. It forms white crystals that exhibit a characteristic, aromatic odor similar to that of naphthalene. Despite its name, it does not contain the element fluorine, but rather it comes from the violet fluorescence it exhibits. For commercial purposes it is obtained from coal tar, where it was discovered and named by Marcellin Berthelot in 1867.

It is insoluble in water and soluble in many organic solvents. Although sometimes classified as a polycyclic aromatic hydrocarbon, the five-membered ring has no aromatic properties. Fluorene is mildly acidic.

Synthesis, structure, and reactivity
Although fluorene is obtained from coal tar, it can also be prepared by dehydrogenation of diphenylmethane. Alternatively, it can be prepared by the reduction of fluorenone with zinc or hypophosphorous acid–iodine. The fluorene molecule is nearly planar, although each of the two benzene rings is coplanar with the central carbon 9.

Fluorene can be found after the incomplete combustion of plastics such as PS, PE and PVC.

Acidity
The C9-H sites of the fluorene ring are weakly acidic (pKa = 22.6 in DMSO.) Deprotonation gives the stable fluorenyl anion, nominally C13H9−, which is aromatic and has an intense orange colour. The anion is a nucleophile.  Electrophiles react with it by adding to the 9-position. The purification of fluorene exploits its acidity and the low solubility of its sodium derivative in hydrocarbon solvents.

Both protons can be removed from C9. For example, 9,9-fluorenyldipotassium can be obtained by treating fluorene with potassium metal in boiling dioxane.

Ligand properties
Fluorene and its derivatives can be deprotonated to give ligands akin to cyclopentadienide.

Uses
Fluorene is a precursor to other fluorene compounds; the parent species has few applications. Fluorene-9-carboxylic acid is a precursor to pharmaceuticals. Oxidation of fluorene gives fluorenone, which is nitrated to give commercially useful derivatives. 9-Fluorenylmethyl chloroformate (Fmoc chloride) is used to introduce the 9-fluorenylmethyl carbamate (Fmoc) protecting group on amines in peptide synthesis.

Polyfluorene polymers (where carbon 7 of one unit is linked to carbon 2 of the next one, displacing two hydrogens) are electrically conductive and electroluminescent, and have been much investigated as a luminophore in organic light-emitting diodes.

Fluorene dyes
Fluorene dyes are well developed. Most are prepared by condensation of the active methylene group with carbonyls. 2-Aminofluorene, 3,6-bis-(dimethylamino)fluorene, and 2,7-diiodofluorene are precursors to dyes.

See also
CataCXium F sulf
Fluorenol
Indecainide
PD-137889
Carbazole
Dibenzothiophene

References

External links
 Fluorene in the National Institute of Standards and Technology database.

Molecular electronics
 
Polycyclic aromatic hydrocarbons
Scannerless parsing. In computer science, scannerless parsing (also called lexerless parsing) performs tokenization (breaking a stream of characters into words) and parsing (arranging the words into phrases) in a single step, rather than breaking it up into a pipeline of a lexer followed by a parser, executing concurrently. A language grammar is scannerless if it uses a single formalism to express both the lexical (word level) and phrase level structure of the language.

Dividing processing into a lexer followed by a parser is more modular; scannerless parsing is primarily used when a clear lexer–parser distinction is unneeded or unwanted. Examples of when this is appropriate include TeX, most wiki grammars, makefiles, simple application-specific scripting languages, and Raku.

Advantages 
 Only one metalanguage is needed
 Non-regular lexical structure is handled easily
 "Token classification" is unneeded which removes the need for design accommodations such as "the lexer hack" and language reserved words (such as "while" in C)
 Grammars can be compositional (can be merged without human intervention)

Disadvantages 
 Since the lexical scanning and syntactic parsing are combined, the resulting parser tends to be more complicated and thus harder to understand and debug. The same will hold for the associated grammar, if a grammar is used to generate the parser.
 The resulting parser tends to be significantly less efficient than a lexer-parser pipeline with regard to both time and memory.

Implementations 
 SGLR is a parser for the modular Syntax Definition Formalism (SDF), and is part of the ASF+SDF Meta-Environment and the Stratego/XT program transformation system.
 JSGLR, a pure Java implementation of SGLR, also based on SDF.
 TXL supports character-level parsing.
 dparser generates ANSI C code for scannerless GLR parsers.
 Spirit allows for both scannerless and scanner-based parsing.
 SBP is a scannerless parser for Boolean grammars (a superset of context-free grammars), written in Java.
 Laja is a two-phase scannerless parser generator with support for mapping the grammar rules into objects, written in Java.
 The Raku grammars feature of the general purpose programming language Raku.
 PyParsing is a scannerless parser written in pure Python.
 META II Has built in token parsers functions.
 TREE-META Like META II also is scannerless having builtin lexer functions.
 CWIC compiler for writing and implementing compilers. Has token rules as part of its language. Rules in CWIC were compiled into Boolean functions returning success or failure.

Notes
 This is because parsing at the character level makes the language recognized by the parser a single context-free language defined on characters, as opposed to a context-free language of sequences of strings in regular languages. Some lexerless parsers handle the entire class of context-free languages, which is closed under composition.

References

Further reading 

Parsing algorithms
Curtiss YA-10 Shrike. The Curtiss YA-10 Shrike (Model 59B) was a 1930s United States test and development version of the A-8 Shrike ground-attack aircraft using various radial engines in place of the inline engine.

Development
The Curtiss YA-10 Shrike was the first YA-8 fitted with a Pratt & Whitney R-1690-9 (R-1690D) Hornet radial engine. The conversion was carried out in September 1932, and it was found that the aircraft's performance was not degraded by the change of engine, and low-level maneuverability was improved due to the lower mass moment of inertia with the short radial engine. The USAAC preferred radials to inline engines for the ground attack role, due to the vulnerability of the latter's cooling system to anti-aircraft fire. The US Navy also preferred radials for carrier-borne operations. Upon completion of testing the Army changed an order for 46 A-8B aircraft to the production version of the YA-10, the A-12 Shrike.

Operational history
Following completion of testing, the YA-10 was assigned to the 3rd Attack Group for operational service, then in 1934 it was assigned to the Command and General Staff School. The YA-10 was scrapped in early 1939.

The XS2C-1 was the Navy's first two-seat warplane. Since it was not equipped for carrier operations, it remained a prototype.

Variants
YA-10 Model 59B, one U.S. Army Air Corps prototype
XS2C-1 Model 69, one U.S. Navy prototype with a  Wright R-1510-28 Whirlwind engine, delivered December 1932

Operators

United States Army Air Corps

Specifications (YA-10)

See also

References

A-10 Shrike
A-10 Shrike
Single-engined tractor aircraft
Low-wing aircraft
Aircraft first flown in 1932
Aircraft with fixed conventional landing gear
Curtiss XA-14. The Curtiss XA-14 was a 1930s United States airplane, the first multi-engine attack aircraft tested by the United States Army Air Corps. Carrying a crew of two, it was as fast as the standard pursuit aircraft in service at the time.

Design and development
Originally built as an in-house venture as the Curtiss Model 76, powered by two experimental Wright XR-1510 radial engines, flight testing was sufficiently impressive that after the USAAC appraisal the Model 76 was returned to Curtiss and fitted with two  Wright R-1670-5 Whirlwind engines with two-position variable-pitch propellers. This configuration was accepted by the Army with the designation XA-14. It had standard Army markings with the serial number 36-146.

The Model 76 was of all-metal construction with an oval section semimonocoque fuselage, described as "pencil slim". The XA-14 was extensively tested, at one stage being fitted with a  cannon in the nose.

In July 1936, 13 developed versions, re-engined with two  Wright R-1820-47 Cyclone 9-cylinder radials, were ordered into production as the Y1A-18.

Specifications (XA-14)

See also

References

Notes

Bibliography

 Eden, Paul and Soph Moeng, eds. The Complete Encyclopedia of World Aircraft. London: Amber Books Ltd., 2002. .
 Fahey, James C. U.S. Army Aircraft 1908-1946. New York: Ships and Aircraft, 1946.
 Fitzsimons, Bernard, ed. The Illustrated Encyclopedia of the 20th Century Weapons and Warfare, Vol. 21. London: Purnell & Sons Ltd. 1967/1969. .
 Swanborough, F. Gordon and Peter M. Bowers. United States Military Aircraft Since 1909. New York: Putnam, 1964. .
 Wagner, Ray. ‘’American Combat Planes, Third Enlarged Edition.’’ Garden City, New York: Doubleday & Company, Inc. 1982 .

A-14
A-14, Curtiss
Mid-wing aircraft
Aircraft first flown in 1935
Twin piston-engined tractor aircraft
Aircraft with retractable conventional landing gear
Fjölnir (programming language). Fjölnir (also Fjolnir or Fjoelnir) is a programming language developed by professor Snorri Agnarsson of computer science at Háskóli Íslands (University of Iceland) that was mostly used in the 1980s. The source files usually have the extension fjo or sma.

Features 

Fjölnir is based on the concept of representing programs as trees, and packages by substitutions on trees using algebraic operators. For example, in the Hello World example below, "GRUNNUR" is a package, the block of code between braces is a package, and * is an operator that substitutes names in one package with elements from another. In this case, skrifastreng (which writes a string to the standard output) is imported from "GRUNNUR".

Code examples 

;; Hello world in Fjölnir

"hello" < main
{
    main ->
    stef(;)
    stofn
        skrifastreng(;"Hello, world!"),
    stofnlok
}
*
"GRUNNUR"
;

External links 
 Fjölnir package (DOS, works in older versions of Windows)
 PDF about Fjölnir (In Icelandic) 
 99 Bottles of Beer in Fjölnir
 The original source for both Fjölnir 1 and Fjölnir 2; coded in Fjölnir itself.

References 

Non-English-based programming languages
Icelandic language
MV Taku. M/V Taku is a Malaspina-class mainline vessel built for the Alaska Marine Highway System. The ship has been retired and was sold to a Dubai-based company for $171,000. The owner sought to sell the ferry internationally, and was unsuccessful, and it was last seen beached in Alang, India, to be scrapped.

History
Designed by Philip F. Spaulding  & Associates, constructed in 1963 by the Puget Sound Bridge & Dry Dock Company in Seattle, Washington, the M/V Taku is named after Taku Glacier which is located just southeast of Juneau, Alaska, and has been in the ferry system for over forty years. In 1981, the Taku received a major refurbishment and was in service steadily until the summer of 2015 when she was laid up due to budget considerations. The AMHS subsequently announced that it would retire the vessel in preparation for sale or scrapping.

Role
As a mainline ferry, Taku served the larger of the inside passage communities (such as Ketchikan, Petersburg, and Sitka), its route primarily stayed between Ketchikan and Skagway in Southeast Alaska.

The M/V Taku was the largest of the three AMHS vessels able to serve the communities of Hoonah and Kake and because of this served as a critical component of providing transportation out of Hoonah and Kake after the "milk run" ferry, the  hit a rock and went into dry dock.

Amenities
The Takus amenities included a hot-food cafeteria; bar; solarium; forward, aft, recliner, movie, and business lounges; gift shop; 8 four-berth cabins; and 36 two-berth cabins.

Accidents and Incidents
 On April 23rd, 1963 the Taku struck a rock outside Petersburg in a minus tide.  She returned to service on May 3rd.
 On August 8th, 1963 two boys entered the wheelhouse when the Taku was preparing to leave Petersburg, and engaged the engines.  The resulting damage to the dock left the vehicle loading ramp out of commission for three months.
 On July 29th, 1970, the Taku ran aground on Kinihan Island, outside of Prince Rupert, Canada. All passengers on board were evacuated safely, and the cars were transferred to the BC Ferry MV Queen of Prince Rupert

Notes

References

External links
 Official Alaska Marine Highway System website
 M/S Taku.

Former Alaska Marine Highway System vessels
1962 ships
Ships built by Lockheed Shipbuilding and Construction Company
Catnic Components Ltd v Hill & Smith Ltd. Catnic Components Ltd. v. Hill & Smith Ltd. [1982] R.P.C. 183 is a leading House of Lords decision on the nature of a patent and in particular the methods of claim construction.

Background
Catnic Components had a patent for a steel lintel, used to provide structural support over a door or window opening in a brick wall. The lintel is hollow, being made from sheet steel pressed into a rectangular or trapezoidal shape with a wind to anchor the device to the surrounding brickwork. Part of the specification required a bar to "extend vertically". Hill & Smith created a virtually identical invention that had a bar that extended at an upwards slant, only 6 or 8 degrees from being completely vertical. Despite the difference the device worked entirely in the same way as Catnic's invention.

Catnic sued for patent infringement. At trial, the judge held there was an infringement under the "pith and marrow" doctrine. The Court of Appeal of England and Wales overturned the ruling as it held that the "vertical" requirement was an exact and essential element of the patent. The Law Lords reversed the decision of the Court of Appeal, finding that there was an infringement, and affirmed the use of purposive construction in patent interpretation.

Opinion of the Court
Lord Diplock held that a patent must be read in a "purposive" manner that focuses on the essential features of the patent. He famously stated:
My Lords, a patent specification is a unilateral statement by the patentee, in words of his own choosing, addressed to those likely to have a practical interest in the subject matter of his invention (i.e. "skilled in the art"), by which he informs them what he claims to be the essential features of the new product or process for which the letters patent grant him a monopoly. It is called "pith and marrow" of the claim. A patent specification should be given a purposive construction rather than a purely literal one derived from applying to it the kind of meticulous verbal analysis in which lawyers are too often tempted by their training to indulge. The question in each case is: whether persons with practical knowledge and experience of the kind of work in which the invention was intended to be used, would understand that strict compliance with a particular descriptive word or phrase appearing in a claim was intended by the patentee to be an essential requirement of the invention so that any variant would fall outside the monopoly claimed, even though it could have no material effect upon the way the invention worked.

See also
 Doctrine of equivalents
 Improver v Remington (1990)
 Kirin-Amgen v Hoechst Marion Roussel (2004)

References

House of Lords cases
United Kingdom patent case law
1982 in United Kingdom case law
Renishaw plc. Renishaw plc is a British engineering company based in Wotton-under-Edge, England. The company's products include coordinate-measuring machines and machine tool products. It is listed on the London Stock Exchange and is a constituent of the FTSE 250 Index.

History
The company was founded by Sir David McMurtry and John Deer in 1973. McMurtry had needed to measure fuel pipes on a prototype jet engine: at the time, coordinate-measuring machine sensors featured rigid styli, which required manual positioning on the surface and which yielded poor repeatability when measuring delicate components.  To meet this need, McMurtry invented a touch-trigger probe device, which he then patented. The probe featured an elegant 'kinematic' location for a spring-loaded stylus, providing a highly repeatable seated position for the stylus combined with the compliance needed to measure such components.

Renishaw floated on the Unlisted Securities Market in 1983, and gained a full listing on the London Stock Exchange in November 1984. In 2006 the Company bought 'itp', a German manufacturer of precision styli. In early 2009 the global recession reached Renishaw, resulting in a large proportion of the workforce being placed "at risk".

In 2010 Renishaw bought a stake (and subsequently took complete control) of Measuring Devices Ltd, a company providing a range of services in the field of surveying equipment. In 2011 Renishaw purchased the 400,000 sq ft Bosch plant in Miskin, Wales.

Operations
The company's product portfolio includes touch probes for CNC machine tools, calibration systems that optimise the performance of CNC machinery, linear encoder systems, rotary encoder systems, additive manufacturing machines, dental CAD/CAM systems, Raman spectroscopy and medical devices for functional neurosurgery applications.

Locations
Renishaw's main offices are situated in Gloucestershire in an old watermill, with several new buildings on a  site.  The company has a machine shop located at Stonehouse, Gloucestershire, and an assembly facility at Woodchester, both near Stroud. There are further assembly facilities in Dublin (Ireland) and Pune (India). Renishaw also has research facilities located in Wotton-under-Edge, Edinburgh and Ljubljana.

Sale of Renishaw
On 2 March 2021, David McMurtry and John Deer indicated that they wished to dispose of their entire holdings in Renishaw, comprising some 53% of the shares, as 'we recognise that neither of us is getting any younger'.  The Renishaw board then announced that it was launching a formal sale process for the entire company. This process was terminated on 7 July 2021, the board concluding that none of the proposals met their objectives.

References

External links
Official site

Engineering companies of the United Kingdom
Companies listed on the London Stock Exchange
Companies based in Stroud, Gloucestershire
Technology companies established in 1973
Wotton-under-Edge
1973 establishments in England
Secondary electrons. Secondary electrons are electrons generated as ionization products. They are called 'secondary' because they are generated by other radiation (the primary radiation). This radiation can be in the form of ions, electrons, or photons with sufficiently high energy, i.e. exceeding the ionization potential. Photoelectrons can be considered an example of secondary electrons where the primary radiation are photons; in some discussions photoelectrons with higher energy (>50 eV) are still considered "primary" while the electrons freed by the photoelectrons are "secondary".

Applications
Secondary electrons are also the main means of viewing images in the scanning electron microscope (SEM). The range of secondary electrons depends on the energy. Plotting the inelastic mean free path as a function of energy often shows characteristics of the "universal curve"  familiar to electron spectroscopists and surface analysts. This distance is on the order of a few nanometers in metals and tens of nanometers in insulators. This small distance allows such fine resolution to be achieved in the SEM.

For SiO2, for a primary electron energy of 100 eV, the secondary electron range is up to 20 nm from the point of incidence.

See also
 Delta ray
 Everhart–Thornley detector

References

Electron states
Ions
Antlerite. Antlerite is a greenish hydrous copper sulfate mineral, with the formula Cu3(SO4)(OH)4. It occurs in tabular, acicular, or fibrous crystals with a vitreous luster. Originally believed to be a rare mineral, antlerite was found to be the primary ore of the oxidised zones in several copper mines across the world, including the Chuquicamata mine in Chile, and the Antler mine in Arizona, US from which it takes its name. It is chemically and optically similar in many respects to other copper minerals such as malachite and brochantite, though it can be distinguished from the former by a lack of effervescence in hydrochloric acid.

Antlerite is a common corrosion product on bronze sculptures located in urban areas, where atmospheric sulfur dioxide (a common pollutant) is present. Antlerite forms mainly in sheltered areas where weathering is low, which permits accumulation of copper ions and enhancement in the acidity of water films. In exposed areas, the main corrosion product is brochantite.

References

Copper(II) minerals
Sulfate minerals
Orthorhombic minerals
Minerals in space group 62