Beam engines.

The first recorded use of the term tappet is as part of the valve gear in the 1715 Newcomen engine, an early form of steam engine. Early versions of the Newcomen engines from 1712 had manually operated valves, but by 1715 this repetitive task had been automated through the use of tappets. The beam of the engine had a vertical 'plug rod' hung from it, alongside the cylinder. Adjustable blocks or 'tappets' were attached to this rod and as the beam moved up and down, the tappets pressed against long levers or 'horns' attached to the engine's valves, working the cycle of steam and injection water valves to operate the engine.  This operation by tappets on a plug rod continued into the early twentieth century with the Cornish engine.  From the 19th century onwards, most steam engines used slide valves or piston valves, which do not require the use of tappets.

Internal combustion engines.

In an internal combustion engine, a tappet (also called a 'valve lifter' or 'cam follower') is the component which converts the rotation of the camshaft into vertical motion which opens and closes the intake or exhaust valve. The types of valve lifters (i.e. tappets) commonly used by automotive engines are solid lifters, hydraulic lifters and roller lifters.  An alternative to the tappet is the 'finger follower', which is a pivoting beam that is used to convert the camshaft rotation into opening and closing of a valve. Finger followers are used in some high-performance dual overhead camshaft engines (instead of bucket tappets), most commonly in motorcycles and sports cars.  To reduce wear from the rotating camshaft, the tappets were usually circular and allowed, or even encouraged, to rotate. This avoided grooves developing from the same point of the tappet always running on the same point of the camshaft. However, in some relatively small engines with many cylinders (such as the Daimler '250' V8 engine), the tappets were small and non-rotating.  Most 'flat' tappets (i.e. without rollers) usually contain a slight radius which creates a subtle mushroom-shaped surface, since a perfectly flat surface leads to'slamming' against a steep camshaft face.

Adjusting the tappets.

A common, yet imprecise, use of the term 'tappet' is the engine maintenance task referred to as "adjusting the tappets" in an overhead valve (OHV) engine, which was a widely used engine configuration between the 1940s and the 1990s. The task involves adjusting the clearance of tappet from the camshaft, however the adjustment is not actually made to the tappets themselves.  On most OHV engines, the adjustment was made by turning a screw set in the end of the rocker that pressed on the end of the pushrod. With the engine rotated to give the widest gap between the camshaft and a particular tappet, the rocker screw was adjusted until this gap was at the correct spacing, as measured with the use of a feeler gauge. If the gap was too wide, this could result in an audible 'tappet rattle' from the rocker cover. If the gap was too narrow, this could result in engine damage such as bent pushrods or burnt valves. The adjusting screw was locked by a locknut. Failure of the locknut to hold the adjustment in place could cause catastrophic engine failure, which has led to fatal aircraft crashes.  On some OHV engines in the 1960s, such as the Ford Taunus V4 engine and Opel CIH engine, the tappet adjustment was done by setting the height of the rocker pivot point (rather than the typical method of a rocker-end adjustment screw). On the 1965-1970 versions of the Opel CIH engine with solid tappets, the tappet adjustment was conducted with the engine running.

Hydraulic tappets.

A hydraulic tappet, also known as a "hydraulic lash adjuster", contains a small hydraulic piston that becomes filled with pressurised engine oil. the piston acts as a hydraulic spring that automatically adjusts the tappet clearance according to the oil pressure. Although the movements of the piston are small and infrequent, they are sufficient to make the valve actuation self-adjusting so that there is no need to manually adjust the clearance of the tappets.  Hydraulic tappets depend on a supply of clean oil at the appropriate pressure. When starting a cold engine, with low oil pressure, hydraulic tappets are often noisy for a few seconds, until they position themselves correctly.

Roller tappets.

Early automotive engines used a roller at the contact point with the camshaft, however as engine speeds increased, 'flat tappets' with plain ends became far more common than tappets with rollers. Some modern high-performance automotive engines use roller tappets, in order to use a camshaft with a steeper profile.

Valvetrain layouts.

Sidevalve engines.

In a sidevalve engine— a common design for car engines until the 1950s— the valves are mounted at the sides of the cylinder and face upwards. This means that the camshaft could be placed directly beneath the valves, without the need for a rocker. With lower cylinder blocks, the tappets could drive the valves directly without needing even a push rod.  Sidevalve engines also required regular adjustment of the tappet clearance, and in this case it was the tappets themselves that were adjusted directly. Small access plates were provided on the sides of the cylinder block, giving access to the gap between the valves and tappets. Some tappets had a threaded adjuster, but simpler engines could be adjusted by grinding down the ends of the valve stem directly. As the tappet adjustment always consisted of expanding the clearance (re-grinding valves into their valve seats during de-coking makes them sit lower, thus reducing the tappet clearance), adjustment by shortening the valve stems was a viable method. Eventually the valves would be replaced entirely, a relatively common operation for engines of this era.

Overhead valve engines.

In an overhead valve engine, the tappets are located down in the engine block and operate long, thin pushrods which transfer the motion (via the rocker arms) to the valves located at the top of the engine.

Single overhead camshaft engines.

In a single overhead camshaft (SOHC) engine, the tappets are located at the top of the cylinder head and usually operate the valves indirectly via rocker arms.  Mass-production of SOHC engines for passenger cars became more common in the 1970s, in the form of crossflow cylinder heads with a overhead rockers located directly beneath a single overhead camshaft, as a more efficient design which could be cost-effectively manufactured. The 1970-2001 Ford Pinto engine was one of the first mass-production engines to use an SOHC design with a toothed cambelt. In this configuration, the rockers combined the function of sliding tappet, rocker and adjustment device. Adjustment of the valve clearance was usually by a threaded pivot stud beneath the rocker. The linear sliding tappets often had a high rate of wear and demanded careful lubrication.  A relatively uncommon design of an SOHC camshaft with four valves per cylinder was first used in the 1973-1980 Triumph Dolomite Sprint inline-four engine, which used a camshaft with 8 lobes that actuated the 16 valves via a clever arrangement of rocker arms.

Double overhead camshaft engines.

Double overhead camshaft (DOHC) engines were first developed as high performance aircraft and racing engines, with the camshafts mounted directly over the valves and driving them through a simple 'bucket tappet'. Most engines used a crossflow cylinder head with the valves in two rows in line with their corresponding camshaft.  The tappet clearance adjustment is typically set using a small shim, located either above or below the tappet. Shims were made in a range of standard thicknesses and a mechanic would swap them to change the tappet gap. In early DOHC engines, the engine would first be assembled with a default shim of known thickness, then the gap measured. This measurement would be used to calculate the thickness of shim that would result in the desired gap. After installation of the new shim, the gaps would then be measured again to verify that the clearance was correct. As the camshaft had to be removed to change the shims, this was an very time consuming operation (especially since the position of the camshaft could vary slightly each time it was re-installed).  Later engines used an improved design where the shims were located above the tappets, which allowed each shim to be changed without removing either the tappet or camshaft. A drawback of this design is that the rubbing surface of the tappet becomes the surface of the shim, which is a difficult problem of mass-production metallurgy. The first mass production engine to use this system was the 1966-2000 Fiat Twin Cam engine, followed by engines from Volvo and the water-cooled Volkswagens.

Other uses.

The term 'tappet' is also used, obscurely, as a component of valve systems for other machinery, particularly as part of a bash valve in pneumatic cylinders. Where a reciprocating action is produced, such as for a pneumatic drill or jackhammer, the valve may be actuated by inertia or by the movement of the working piston. As the piston hammers back and forth, it impacts a small tappet, which in turn moves the air valve and so reverses the flow of air to the piston.  In weaving looms, a tappet is a mechanism which helps form the shed or opening in the warp threads (long direction) of the material through which the weft threads (side to side or short direction) are passed. The tappets form the basic patterns in the material such as plain weave, twill, denim, or satin weaves. Harris tweed is still woven on looms in which tappets are still used.

A tappet is most commonly a component in an internal combustion engine which converts the rotating motion of the camshaft into linear motion of the valves, either directly or indirectly.


Early life.

Hermann Simon was born in Berlin in 1949, the son of classical philologist and philosophy historian Marie Jalowicz-Simon and the Judaizers Heinrich Simon. Hermann Simon grew up in East Berlin. His family was a member of the Jewish Community East Berlin, but which was very small because of the Holocaust and emigration in the postwar years. He studied at the Humboldt University in Berlin History and Oriental Studies, followed by graduate studies in Prague.

Career.

From 1975 to 1988 he worked at the Numismatic Collection of the National Museums in Berlin. In 1988 he was involved in the first exhibition about Jewish life that in East Berlin (in Ephraim Palais was shown).  Since the establishment of the New Synagogue Berlin - Centrum Judaicum in the same year he was its director. On 1 September 2015, he handed over the reins to his successor Anja Siegemund. In 2015 Simon was awarded the Order of Merit of Berlin.  In the Berlin community, he is next to Andreas Nachama as representatives of the "liberal wing".

Family.

Hermann Simon is married to Deborah born Rix and lives with his family in Berlin.

Selected publications.

German.

Hermann Simon beschäftigt sich in seinen zahlreichen Publikationen insbesondere mit Problemen der Geschichte der Juden in Deutschland. Er ist u. a. Herausgeber der Reihen "Jüdische Miniaturen", "Jüdische Memoiren" und der Schriftenreihe des Centrum Judaicum. Außerdem veröffentlichte er einige Artikel im Bereich Numismatik und Kataloge zu Berliner Ausstellungen.

Hermann Simon (born 1949) is a German historian who was for 27 years director of the Foundation "New Synagogue Berlin - Centrum Judaicum".


Passenger numbers.

In the year to 30 June 2011 the airport had 316,000 domestic and 46,000 international passengers. In 2017/18 there were 353,000 passengers, all domestic, 54% of them to Wellington and 37% to Christchurch. Hamilton is the eleventh-busiest airport in New Zealand by passenger traffic.

History.

The airport is on land owned by Samuel Steele (brother of William Steele, who brought militia-settlers from Sydney to Hamilton in 1864) from about 1880. By 1929 there was a landing ground on the farm, though a site close to the city was also considered. In 1935 Steele's aerodrome was sold for expansion into an airport and opened by the mayor on 12 October.  As the world prepared for war, it became clear that a landing strip needed to be constructed in the Hamilton area. By 1935, the air strip was already in service, as a stopover for military aircraft that would land after a long journey. Services provided refueling as well as food and rest for the incoming pilots.  Travel by air began to blossom soon after the war was over, and, in 1950, the airport received its first commercial flight. The main runway was sealed in 1965, and turboprop flights began to Hamilton that year, with NAC's Fokker Friendship aircraft operating. The runway was further lengthened to accommodate Vickers Viscount, 1970, and ultimately Boeing 737 aircraft types in 1975.  In 1989, the New Zealand government sold the airport to councils representing Hamilton City (50 per cent), Waikato District (15.625 per cent), Waipa District (15.625 per cent), Matamata-Piako District (15.625 per cent) and Ōtorohanga District (3.125 per cent). This development led to unprecedented growth for the airport.  Ansett New Zealand built an independent passenger terminal to the south of the main building, equipping it with a 'Golden Wing Club' lounge and food vending machines. The airline's "Ansett NZ" division operated flights to Wellington from Hamilton from 1995 until 2000, when Ansett NZ was sold to a New Zealand business consortium and rebranded Qantas NZ, with their own New Zealand domestic flights division. "Qantas NZ" operated at the airport until 2001, when it went into receivership. The terminal was then occupied by Origin Pacific airlines. This airline operated domestic services until it too went bankrupt in 2004. The small terminal was then left unused.  In 1998, Hamilton Airport Motor Inn was developed to cater for travellers using the airport.  A NZ$15.3 million terminal expansion begun in 2005 featured a 60 per cent increase in floorspace with improved baggage handling areas, better international and domestic check-in space, and passenger security screening. It was completed in late 2007.  Hugh McCarroll was the airport's chief executive from the early 2000s until retirement in February 2006. The current chief executive is Chris Doak, formerly growth and development general manager for electricity utilities company WEL Networks.

Trans Tasman services.

In 1994, the airport became a terminal for Trans Tasman air routes, with charter flights provided on Boeing 727s by Kiwi Travel International Airlines (not to be confused with the United States-based Kiwi International Air Lines) which served Brisbane, Sydney and Melbourne. New Zealand's Kiwi went bankrupt in 1996, but by that time Freedom Air had begun flying the same routes with Boeing 737 aircraft. They also, briefly, operated flights to Nadi, Fiji, in 2005. Freedom Air ultimately decided to make Hamilton International Airport their company hub until parent company Air New Zealand closed the airline down on 30 March 2008 operating its own full service instead. By then, the Airbus A320 was being operated. When passenger numbers dropped to an unsustainable level in August 2009, Air New Zealand ceased services to Australia. Virgin Australia attempted to fill the need for a trans Tasman service later that year with twice-weekly Boeing 737-800 flights to Brisbane; however, passenger numbers remained low and Virgin Australia ended flights on 27 October 2012. No further international flights have been made from the airport since that date.

Flight training.

Hamilton Airport is home to the New Zealand Training Centre of L3Harris Airline Academy. L3Harris Airline Academy is the British flight training division of L3Harris that provides freshly trained airline pilots to numerous airlines throughout the world, mainly within the United Kingdom, most notably EasyJet, and also including British Airways, Qatar, Flybe, Thomson, Oman and, formerly, Thomas Cook and Monarch Airlines among others. Most of the non-passenger traffic at this airport is generated by L3Harris training flights, in single-engined Diamond DA20 and Cessna 172, and twin-engined Diamond DA42 Twin Star aircraft.  The Waikato Aero Club has been based at Hamilton Airport since 1933. The club provides a full range of flight training from recreational flying in Light Sport Aircraft through to commercial Multi-Engine IFR.

Capabilities.

The airport currently accommodates many different types of aircraft, from piston-engined light aircraft to commercial turboprop aircraft such as the ATR 72. The airport can handle all light business jets as well as 40-to-80-seat regional jets such as the Embraer E195 and Bombardier CRJ200. Several airliners can operate from the airport including the 100-200 seat Boeing 737, Boeing 757 and Airbus A320. The largest aircraft authorised to land at Hamilton is the 150-to-250-seat Boeing 767. Plans to increase runway length from 2,195m to 3,000m to attract larger aircraft and start Asian regional flights, have been considered.  The airport operates 24 hours a day, seven days a week.  In August 2011, approval was received by Hamilton International Airport to extend its runway up to 3,000 metres—the same size as secondary airports in other parts of the world, such as the Gold Coast. It will finish before 15 years' approval ends.  The airport has a single terminal building and 6 tarmac gates. The apron is capable of accommodating up to five A320/737-800 aircraft at once.

Hamilton Airport is an airport located 14 kilometres south of the city of Hamilton in the Waikato region, in New Zealand. It is sited at Rukuhia, which was the name of the Royal New Zealand Air Force base on that site during World War II.


History.

The history of the seven-string guitar stretches back more than 230 years. During the Renaissance period (c. 1400–1600 CE), the European guitar generally had four courses, each strung with two gut strings, and the pair of strings within each course tuned in unison. By the mid-Baroque period (c. 1600–1750), it more commonly had five courses (still double-strung) and used a variety of tunings, some of them re-entrant. By the early eighteenth century, six double-strung courses had become common.  Up to this point, most stringed instruments were strung with gut strings. At around 1800, quality metal-wire strings became widely available. These new strings were more durable, remained in tune better and, most importantly, produced a "louder" sound than the traditional gut strings. As use of metal strings became more widely adopted, their greater volume output impelled luthiers to experiment more with single-strung courses on their instruments and, in a relatively short time, the modern practice of using six single strings became first common, and then standard. The changing number of courses in these early guitars may also illustrate an ongoing desire on behalf of players to increase the range of the instrument, a development similar to that gone through by the lute in earlier days. It is likely that all of these factors contributed to the development of the seven-string guitar, which has been around ever since. The seven-string guitar never became as widely accepted in Europe as the six-string instrument, but a number of composers did produce a significant body of work for the seven string. French guitarist Napoleon Coste (1805–1883) composed works with a seven-string guitar specifically in mind. The Italian guitarist Mario Maccaferri (1899–1993) was a celebrated advocate of bass strings (diapasons or bourdons) and also composed for the instrument. By contrast, in Russia the seven-string guitar became widely popular, and entire schools of playing were developed around its use. Despite some brief setbacks in the mid-20th century, during which six-string instruments rose in prominence, the seven-string Russian guitar has remained popular in Russia to this day. In the New World, a or —with fourteen strings, strung in seven double courses—has been known in Mexico since at least 1776 (Antonio Vargas). These instruments may still be found in use in Mexico, although the modern six-string instrument has become far more common. Seven-string instruments retain current popularity in parts of South America, notably Brazil, where they became an important instrument in the "choro" music of the 19th century, which is currently (2015) experiencing a revival.

Acoustic designs.

Russian.

The Russian guitar or gypsy guitar is a seven-string acoustic guitar tuned to the open G tuning (DGBDGBD), which arrived or was developed early in the 19th century in Russia, possibly as a development of the cittern, the kobza and the torban. It is known in Russia as the semistrunnaya gitara ("семиструнная гитара") or affectionately as the semistrunka ("семиструнка").  Its invention was popularized by Andrei Sychra, who also wrote a method for the guitar, as well as over one thousand compositions, seventy-five of which were republished in the 1840s by Stellovsky, and then again in the 1880s by Gutheil. Some of these were published again in the Soviet Union in 1926. Andrei Sychra in his notation, marks with a number between 1 and 4 where to fret the 7th string with the thumb. Another way that Andrei Sychra took advantage of this guitar's innovation was through natural harmonics. Because of the three strings tuned to D, harmonics could be played in synchronization.  Early instruments used gut, and later silk strings; rarely wire. In the 20th century these instruments commonly used nylon strings, like western classical guitars, though by the last third of the century both nylon-strung "classical" and metal-strung "gypsy" versions of the instrument were both plentiful. Whatever material was used for stringing, the Russian guitar is traditionally played without a pick, using fingers for either strumming or picking. The origins of the 7 string most likely came from the English "guittar" popular in the late 18th century. The added string created an extra dimension for bass notes as well as opening up chord possibilities. The seventh string is also likely to have been influenced by the harp as it is meant to played arpeggiated. It also happens that the open D tuning was a perfect fourth lower than the six string tuning. The open D string tuning of this guitar was convenient for many Russian folk songs and dances that were typically within the major key. Along with the added interval possibilities came new techniques not previously seen with 6th string guitars.  The Russian version of the seven-string guitar has been used by professionals, because of its great flexibility and its sound, but has also been popular with amateurs for accompaniment (especially Russian bards) due to the relative simplicity of some basic chords and the ease of playing alternating bass lines. While greatly popular in Russia and Ukraine, this type of guitar has only recently been generating some interest outside of its traditional homeland.  The earliest music published for a seven-string guitar was in St. Petersburg, Russia, on 15 December 1798. The school was owned by Ignác František Held (1766, Třebechovice pod Orebem, Bohemia – 1816, Brest-Litovsk, Russia).  Standard tuning for the Russian guitar is: D2 G2 B2 D3 G3 B3 D4 with a very common "classical" variant being C2 G2 B2 D3 G3 B3 D4  Other tunings include:

Brazilian.

The Brazilian seven-string guitar () is an acoustic guitar used primarily in choro and samba. It was introduced to Brazil in the late 19th century as a steel string guitar. The style of "baixaria" counterpoint and accompaniment technique was developed throughout the 20th century, especially by Dino 7 Cordas and Raphael Rabello. In the early 1980s, guitarist Luiz Otavio Braga had a nylon string version made, and this has become the norm for most contemporary choro musicians such as Yamandu Costa.  The Brazilian seven-string guitar is typically tuned like a classical guitar, but with an additional C below the low E as follows: C2 E2 A2 D3 G3 B3 E4; although some musicians tune the C down to a B resulting in: B1 E2 A2 D3 G3 B3 E4.

Classical.

Seven-string guitarists are utilized in playing traditional and contemporary "classical" repertoire. These instruments are essentially nylon-strung classical guitars with one extra (usually) bass string, and the tuning is most commonly: B1 E2 A2 D3 G3 B3 E4. Aficionados of the instrument have produced many new arrangements traditionally six-string classical guitar pieces, and the seventh string may be retuned—to C or D, for example—to accommodate these arrangements. The use of this instrument in the classical world, along with other extended range instruments having 8, 9, 10, 11, or more strings, has become common enough that several noted string manufacturers now produce and marked string sets specifically for seven-string classical guitars (La Bella; Pyramid; d'Aquisto; etc.) For example, Napoleon Coste arranged one of Franz Schubert's pieces with vocal accompaniment despite guitars being typically for solo performance at the time.

Mexican ().

There is a guitar of seven courses with double string guitar, totaling 14 strings, known as. The instrument is still played in Mexico, though it has become uncommon.

Electric designs.

Semi-hollow and hollow body electric guitars.

In the United States, the jazz guitarist George Van Eps had a seven-string guitar built for him by Epiphone Guitars in the late 1930s and a signature Gretsch seven-string in the late 60s and early 70s. The Van Eps signature guitar may be the first regular-production seven-string electric guitar. Van Eps tuned his 7th string to A.  Several others began using seven-string guitars after Van Eps, including Bucky Pizzarelli, Howard Alden, Ron Eschete, Chance Russell, and John Pizzarelli, son of Bucky Pizzarelli. Lenny Breau also used seven string instruments, but whereas the other players all used instruments with an added bass string, Breau had at least one instrument in which the seventh string was an added "treble" string, tuned to the 'A' above the high 'E' string (A4). At the time he began using the high A string, no commercially manufacturered string could withstand being tuned that high, so Breau substituted a piece of monofilament fishing line of appropriate gauge. A year later advances in materials science allowed the La Bella company to begin manufacturing a custom string for Breau's high A.  Seven-string semi-acoustic archtop guitars were used by jazz-guitarist Ralph Patt after he began exploring major-thirds tuning in 1964. Patt's tuning is a regular tuning, in the sense that all of the intervals between its successive open strings are major thirds; in contrast, the standard guitar-tuning has one major-third amid four fourths. Major-thirds tuning has a smaller scope than standard guitar-tuning, and so Patt started using seven-string guitars, which enabled major-thirds tuning to have the E-e' range of the standard tuning. He first experimented with a wide-neck Mango guitar from the 1920s, which he modified to have seven strings in 1963. In 1967 he purchased a seven-string by José Rubio.  The first seven-string electric guitars were built in the "hollowbody" or "semi-hollow" archtop styles, where the guitar has a central resonating chamber, or a central block with resonant chambers on the sides. This gave the guitar the dark woodiness, breath, and richness that is associated with traditional "jazz" tone, but also made prone to feedback at high volumes, making it problematic for rock guitar playing.

Solid body electric guitars.

In the early thirties the National String Instrument Corporation offered seven-string versions of their solid-body lap-steel guitars.  A solid body seven-string electric guitar was conceived by guitarist Lenny Breau and built by luthier Kirk Sand, debuting at the 1983 NAMM convention featuring a high A-string (rather than the low A-string of Eps). In 1987, Fender signed an agreement with Alex Gregory to produce a Stratocaster-style guitar that featured a high A-string. A small number of prototypes were made. However the unit was never put into production.  The first mass-produced seven-string was the Ibanez UV7 as a signature model for Steve Vai. It was also used by John Petrucci, Reb Beach and Korn amongst others. Vai was drawn to the idea for much of the same reasons seven-string classical and jazz players were—the extended range the additional string offered. After initial experimentation with a high A, a low B was added as the high A proved to be too prone to breaking. (Kirk Sand and Lenny Breau solved the breaking high A string problem by shortening the scale length to 22.75", Vai's Ibanez is 25.5".) Vai began touring with Whitesnake with a seven-string prototype, and then used the guitars for his 1990 release "Passion and Warfare".  The seven-string guitar became prominent when the band Korn featured Ibanez Universe guitars on their 1994 debut album. During the 1990s, manufacturers of 7-strings included Fender's subsidiary Squier and Gibson's subsidiary Epiphone.  In this time many guitarists were introduced to the extended range offered by a seven-string guitar. This was somewhat offset by a growing stigma that a seven-string guitar was a "nu metal" instrument, fit only for heavy riffing. This was ironic as Korn guitarists Munky and Head remember being told in their early days that the seven-string guitar could not be used for riffing, as it was a guitar for technical guitar players.  In the 1990s, several other heavy metal guitarists began using seven-string instruments (notably John Petrucci, Trey Azagthoth, and Erik Rutan), seeing the possibility for detuned riffing while preserving the full upper range of the guitar for solos. However, the seven-string guitar failed to really catch on at this phase in its development, and the Universe model was discontinued briefly in 1995. Historically, Matt Bellamy from Muse had used a custom red Manson seven-string to play just one song, "Citizen Erased", with a AADDGBE tuning (the song was originally recorded on a detuned six-string). However, he later started using new Manson custom seven-strings to play new songs "Supremacy", "Survival" and "Liquid State" on Muse's 2012 "The 2nd Law" album tour. Dino Cazares uses custom seven-string Ibanez guitars; Christian Olde Wolbers has his own signature Jackson seven-string guitar, Jeff Loomis has a signature model made by Schecter and Stephen Carpenter has several of his own models released by ESP.

Hybrid designs.

In the early 2000s, Roger McGuinn (renowned for his skills on the twelve-string guitar and for his long association with The Byrds) worked with C. F. Martin & Company to develop a seven-string folk guitar. McGuinn's guitar (currently being marketed by Martin) is tuned the same as a standard folk guitar with steel strings, but the third (G) string is augmented with a high octave string. Many of McGuinn's notable guitar solos utilize the G string of the twelve-string guitar to perform the main melody, and therefore the Martin seven-string guitar was designed to achieve this extended range playing without the need for doubling all six of the guitar's strings.  In 2010, Inox Guitars has created a mix of the Brazilian Viola caipira and the Russian semistrunka (семиструнка). This instrument has 2 bass strings (as the 6th and 7th strings of the semistrunka) and five treble courses (as the Viola caipira) and it is used in open tuning (GDGDGBD) as a slide guitar.

Tuning.

The 7-string guitar of today is frequently tuned with a lower B on the added seventh string (B1–E2–A2–D3–G3–B3–E4), but other common tunings exist. Many jazz and metal musicians tune in dropped A tuning (A1–E2–A2–D3–G3–B3–E4) for improved bass lines and easier power chords. Choro players usually tune the seventh string up a half-step, to C: C2-E2-A2-D3-G3-B3-E4. The common Russian guitar tunings given above are still in widespread use. And players who prefer an added "treble" string (instead of an added bass string) usually tune: E2–A2–D3–G3–B3–E4–A4.

Uses.

Seven-string guitars are used in a variety of musical styles including Classical, Jazz, Rock, Progressive Rock, and Heavy Metal. The Seven-string works well in a band setting, as its lowest note, B1 lines up well with the B0 commonly used for the lowest note of a 5+ string bass. Both the guitar and bass could drop tune as well using a lowest note of A1 and A0 respectively (with the bass this extends the range to the lowest note on a standard piano).

The seven-string guitar adds one additional string to the more common six-string guitar, commonly used to extend the bass range (usually a low B) or also to extend the treble range.


Biography.

Grötschel was born in Schwelm, Germany, and earned a diploma in mathematics with minor in economics in 1973 from the University of Bochum. He completed a doctorate in 1977 at the University of Bonn under the supervision of Bernhard Korte, and obtained his habilitation at Bonn in the field operations research in 1981. One year later he was appointed full professor for applied mathematics at the University of Augsburg. From 1991 until his retirement at the end of September 2015 he was, while also engaged at ZIB, full professor for information technology at Technical University Berlin. Martin Grötschel was a member of the Executive Committee of the German Mathematical Society (Deutsche Mathematiker-Vereinigung (DMV)) from 1989 to 1996 and from 1993 to 1994 its President. From 1999 to 2014 he was a member of the Executive Committee of the International Mathematical Union (IMU) and from 2007 to 2014 IMU's General Secretary. Since 2011 he has been a member of the Executive Board of the and was from 2011 to 2015 its Chair. He was co-founder and longstanding Chair of the DFG Research Center Matheon "Mathematics for key technologies".  Martin Grötschel has been married since 1976 with his wife Iris Grötschel and has three daughters.

Work.

Martin Grötschel is one of the most internationally renowned experts in the field of combinatorial optimization.  Martin Grötschel's main mathematical research fields are graph theory, linear and mixed-integer optimization and operations research. Already in his doctoral thesis, Grötschel achieved significant progress in the development of solution methods of the Traveling Salesman Problem, in particular, he contributed significantly to understanding the cutting-plane method. His publications together with L. Lovász and A. Schrijver on the ellipsoid method and its application in the combinatorial and convex optimization gained worldwide recognition.  In recent years Martin Grötschel has mainly dealt (besides addressing "classical" mathematical problems) with mathematical modelling and solving real-world problems in economy and industry. The application areas he has worked in include optimization of production planning and control, public transport and energy systems, logistics and telecommunication.  Since the early 1990s Grötschel has been working intensively in the fields electronic information and communication, library systems, Open Access and Open Science and thereto participated in numerous national and international bodies and initiatives.  The promotion of digital humanities is one of the main goals of Grötschel's BBAW presidency.

Awards and honors.

Grötschel was one of the winners of the Fulkerson Prize of the American Mathematical Society in 1982 for his work with László Lovász and Alexander Schrijver on applications of the ellipsoid method to combinatorial optimization. In 2006 the same trio won the John von Neumann Theory Prize of the Institute for Operations Research and the Management Sciences.  The Society for Industrial and Applied Mathematics and Mathematical Optimization Society gave Grötschel the George B. Dantzig Prize in 1991, and the Deutsche Forschungsgemeinschaft gave him the Gottfried Wilhelm Leibniz Prize in 1995. In 2004 he was awarded the EURO Gold Medal, the highest distinction within Operations Research in Europe. He was an invited speaker at the 2006 International Congress of Mathematicians.  Grötschel received honorary doctorates from the University of Karlsruhe in 2006, from the Vietnamese Academy of Sciences and Technology (VAST) in 2007, from the Otto-von-Guericke-Universität Magdeburg in 2008 and from the University of Augsburg in 2011. Since 2011 he has been Distinguished Affiliated Professor of Technical University of Munich.  Grötschel is member of seven national and international scientific academies: In 1995 he was a member the Berlin-Brandenburg Academy of Sciences and Humanities, in 1999 he became Foreign Member of the US National Academy of Engineering (NAE) for "contributions to combinatorial optimization and its applications", since 2003 he has been a member of the Deutsche Akademie der Technikwissenschaften (acatech), since 2005 of the German National Academy of Sciences Leopoldina, since 2015 of the Chinese Academy of Sciences (CAS) as Foreign Member, since 2016 of The World Academy of Sciences (TWAS) for the advancement of science in the developing countries as Fellow, and in 2017 he was elected a member of the Academy of Europe Academia Europaea.  In 2013, a festschrift was published in his honor.

Martin Grötschel (born 10 September 1948) is a German mathematician known for his research on combinatorial optimization, polyhedral combinatorics, and operations research. From 1991 to 2012 he was Vice President of the Zuse Institute Berlin (ZIB) and served from 2012 to 2015 as ZIB's President. Since October 2015 he has been President of the Berlin-Brandenburg Academy of Sciences and Humanities (BBAW).


Engineering.

The earlier cars used a Rover engine from the 1948 Rover 75. A four-speed manual transmission was used with a column-mounted gear change at first and floor-mounted unit from September 1953. At first the gearbox only had synchromesh on third and top but it was added to second gear as well in 1953. A freewheel clutch, a traditional Rover feature, was fitted to cars without overdrive until mid-1959, when it was removed from the specifications, shortly before the London Motor Show in October that year.  The cars had a separate chassis with independent suspension by coil springs at the front and a live axle with half-elliptical leaf springs at the rear. The brakes on early cars were operated by a hybrid hydro-mechanical system but became fully hydraulic in 1950. Girling disc brakes replaced drums at the front from October 1959.  The complete body shells were made by the Pressed Steel company and featured aluminium/magnesium alloy (Birmabright) doors, boot lid and bonnets. If the handle was not used to close them they were easily dented so for the final 95/110 models steel was used instead. The P4 series was one of the last UK cars to incorporate rear-hinged "suicide" doors.

Rover 75.

Announced by Managing Director Spencer Wilks on 23 September 1949 the new Rover 75, now the only Rover in production, was first displayed at the opening day of the Earls Court Motor Show on 28 September 1949. It featured unusual modern styling in stark contrast with the outdated Rover 75 (P3) it replaced. Gone were the traditional radiator, separate headlamps and external running boards. In their place were a chromium grille, recessed headlamps and a streamlined body the whole width of the chassis. A steering column-mounted gear lever was fitted.  The car's styling was derived from the then controversial 1947 s. The Rover executives purchased two such vehicles and fitted the body from one of them to a prototype P4 chassis to create a development mule. James Taylor's book 'Rover P4 – The Complete Story' says that this vehicle was affectionately known as the 'Roverbaker' hybrid.  Malcolm Bobbit states "The P4 set the seal on the future with a vengeance. Rover defied its critics with the P4's new look and to get some idea of the shock of the new, consider some of its rivals... astonishment at the P4's courageous styling." The P3 had almost no boot at all yet that had been considered rather more than adequate. The new car's bonnet-like extension to its rear was ridiculed; the driver sat well forward looking out over a relatively short bonnet and the rear wheels were set well back behind the back seat. All the new car's proportions were different from all the other new cars.  Another, at the time minor, distinctive feature but this one did not catch on was the centrally mounted light in the grille where most other manufacturers of good quality cars provided a pair, one fog and one driving light often separately mounted behind the bumper. Known as the "Cyclops eye" it was discontinued in the new grille announced 23 October 1952.  Power came from a more powerful version of the previous model's 2.1 L (2103 cc/128 in3) Rover IOE straight-6 engine now with chromium-plated cylinder bores, an aluminium cylinder head with built-in induction manifold and a pair of horizontal instead of downdraught carburetters. A four-speed manual transmission was used with a column-mounted gear lever which was replaced by a floor-mounted mechanism in September 1953.  A car tested by "The Motor" magazine in 1949 had a top speed of and could accelerate from 0– in 21.6 seconds. A fuel consumption of was recorded. The test car cost £1106 including taxes. The turning circle was.

Road & Track.

"... and I honestly believe (barring the Rolls-Royce) that there is no finer car built in the world today." Bob Dearborn, Tester Road & Track. Road test no. F-4-52, August 1952.

Broader range.

After four years of the one model policy Rover returned to a range of the one car but three different sized engines. In September 1953 it announced it would supply a four-cylinder Rover 60 and a 2.6-litre Rover 90 adding them to the 75's 2.1-litre six. Rover's stated intention was "to cater for a wider field of motorists who require a quality car with varying degrees of economical running costs and performance".  On the same day there were modifications announced which were accordingly shared by all three:  Rover also announced an all-round reduction in Rover and Land-Rover prices. This was a response to a slump in both home and export sales of all British cars.<br> The "" IOE engine continued.

New engine.

The Rover 75 engine was enlarged in October 1954 to a 2.2 L (2230 cc/136 in3) version of the IOE engine.

Bigger boot.

An updated body for all Rovers was announced 7 October 1954 with major styling changes by David Bache  At the same time Rover's chairman revealed a new factory was being built to double Land-Rover production.

Separate chairs.

In September 1955 the choice of a different style of front seat, two individual seats independently adjustable, was made available on all three cars at extra cost.

Revised front mudguards.

The line of the front mudguards "which", said The Times, "previously gave the car a somewhat blunt appearance" was rearranged with the side lamps and flashing indicators in different positions. A small chrome reflector on the headlamp rim allowed the driver to know the side lights were functioning. Overdrive was made an option. These amendments were announced 11 September 1956.

Rover 60.

The Rover 60 was announced 24 September 1953 to add a more economical four-cylinder engine to Rover's range though leaving trim and equipment the same as the 75 and the new Rover 90 announced at the same time. Rover's idiosyncratic central gear change lever designed to allow three-abreast seating in front was used for this new car. Its 2.0 L (1997 cc/121 in3) engine had been used in the early Land Rover though it now had modifications including an SU carburettor. As the block was shorter than that of the 6-cylinder engine, it sat further back in the frame, and this is sometimes held to have resulted in better handling and compensated for the lack of power.  The Rover 60 shared with the Rover 75 and Rover 90 the October 1954 modifications: a bigger boot, wide rear window and flashing directions indicators all announced at the Paris Motor Show. Independently adjustable separate front seats were made available at extra cost from September 1955.  In the same way Rover 60 buyers were given the choice of a different style of front seat, two individual seats independently adjustable, available at extra cost from September 1955.  Similarly in September 1956 the shape of the front mudguards was rearranged with the side lamps and flashing indicators in different positions. A small chrome reflector on the headlamp rim allowed the driver to know the side lights were functioning. Overdrive was made an option.  In their test of the Sixty in 1954 "The Motor" magazine recorded a top speed of and acceleration from 0– of 26.5 seconds. A fuel consumption of was recorded. The test car cost £1162 including taxes.  The Rover 60 was replaced by the Rover 80 which used an updated version of the overhead-valve 2286 cc (138 in3) four used in the Land Rover of that time. The Rover 80 was announced 24 October 1959.

Rover 90.

The top-end Rover 90 appeared with a much larger more powerful inline-six at the same time, 24 September 1953 as the four-cylinder Rover 60 was introduced. Rover's idiosyncratic central gear change lever designed to allow three-abreast seating in front was used for this new car. This engine produced 90 hp (67 kW) and could propel the car to reach 90 mph (145 km/h). It has a cast-iron block with an aluminium alloy head, a bore and stroke of by and a 6.73:1 compression ratio. This was upped to 7.5:1 in 1956.  Rover's stated intention was to cater for a wider field of motorists requiring varying degrees of performance and running costs.  The Rover 90 shared with the Rover 60 and Rover 75 the October 1954 modifications: a bigger boot, wide rear window and flashing directions indicators all announced at the Paris Motor Show.  The 1956 model was launched in September 1955. Independently adjustable separate front seats were made available at extra cost and at the same time the engine's compression ratio was increased from 6.73:1 to 7.5:1, lifting power by 3 horsepower to 93. Free-wheel was dropped and Laycock de Normanville electric overdrive made available. More sensitive power brakes were provided of a redesigned pattern. The recesses in the 'B' pillars that previously housed the trafficators in pre-1955 models were deleted in this update. Pleats were added to the seats, this treatment continued on subsequent P4 models.  In September 1956 the shape of the front mudguards was rearranged with the side lamps and flashing indicators in different positions. A small chrome reflector on the headlamp rim allowed the driver to know the side lights were functioning.  Testing the Ninety in 1954 "The Motor" magazine recorded a top speed of and acceleration from 0– of 18.9 seconds. A fuel consumption of was recorded. The test car cost £1297 including taxes.  A road test of a Ninety published in "MotorSport" magazine in September 1956 described the engine as virtually inaudible when idling but the steering was "spongy and heavy" and "the roll when cornering was considerable" nevertheless, reported "MotorSport", firm suspension caused "very appreciable column shake and body judder". An owner of a Ninety at the time noted that although the suspension was very soft and comfortable on a straight road on bends the car would "wallow" over and made one feel a bit queasy.  When it was replaced by the Rover 100 in October 1959, 35,903 had been produced, making the Rover 90 the most popular car of the P4 series.

Rover 105R, 105S & 105.

Announced 16 October 1956, the 105R and 105S used a high-output, 8.5:1 compression version of the "" engine used in the 90. The higher compression was to take advantage of the higher octane fuel that had become widely available. This twin-SU carburettor engine produced 108 hp (80 kW). Both 105 models also featured the exterior changes of the rest of the range announced a month earlier. The 105S featured separate front seats, a cigar lighter, chromed wheel trim rings and twin Lucas SFT 576 spotlamps. To minimise the cost of the 105R, these additional items were not standard, however they were provided on the (higher priced) 105R De Luxe.  The 105R featured a "Roverdrive" automatic transmission. This unit was designed and built by Rover and at the time was the only British-built automatic transmission. Others had bought in units from American manufacturers such as Borg-Warner. This unit was actually a two-speed automatic (Emergency Low which can be selected manually and Drive) with an overdrive unit for a total of three forward gears. The 105S made do with a manual transmission and Laycock de Normanville overdrive incorporating a kick-down control. The 105S could reach a top speed of 101 mph (163 km).  "The Motor" magazine tested a 105R de luxe in 1957 and found it to have a top speed of and acceleration from 0– of 23.1 seconds. A fuel consumption of was recorded. The test car cost £1696 including taxes of £566.  Production of the 105 line ended in 1958 for the 105R and 1959 for the manual transmission 105S, 10,781 had been produced, two-thirds with the manual transmission option. For 1959 the manual model was described simply as a 105 and the trim and accessory level was reduced to match the other models.  When the Rover 100 was announced in October 1959 it was described as the replacement for the Rover 90 and the Rover 105.

Rover 80.

The 3-litre P5 car introduced in September 1958 was in full production and the obsolescent P4 range was reduced to just two cars, this new four-cylinder 80, announced on 24 October 1959 and the Rover 100 announced at the same time. The 80 engine was a new Land Rover-derived straight-four overhead-valve engine displacing "", entirely different from the units used in all the other models. With 80 hp (59 kW) available, the car could top 85 mph (137 km/h). Girling vacuum servo-assisted disc brakes at the front were new, and the car used wider tyres and had updated styling. Overdrive, operating on top gear only, was standard on the four-speed transmission. Options included a radio, two tone paint schemes, and either a bench or individual front seats. These options also apply to the 100 (see below).  The four-cylinder cars were never popular, and just 5,900 had been built when, after 3 years, production ended. Its place was taken by the new Rover 95 announced September 1962.  "The Motor" magazine tested an 80 in 1961 and recorded a top speed of and acceleration from 0– of 22.4 seconds. A fuel consumption of was found. The test car cost £1396 including taxes of £411.

Rover 100.

The Rover 90 and Rover 105 were replaced by the more powerful 100 announced on 24 October 1959. Its new but similar IOE straight-6 engine was a short-stroke version of the P5 3-Litre unit. The 100 could reach 100 mph (161 km/h). The interior was luxurious, with wood and leather accents on traditional English car elements like a curved "Shepherds Crook" handbrake lever. A bench front seat or individual front seats could be ordered. A heater was a standard fitting. Like the smaller 80 version, the 100 was fitted with servo-assisted Girling disc brakes at the front, keeping drum brakes at the rear. Overdrive, on top gear only, was a standard fitting.  Production ended in 1962, by which time 16,521 had been produced.  Testing the 100 in 1960, "The Motor" magazine recorded a top speed of, acceleration from 0– of 17.6 seconds and a fuel consumption of. The test car cost £1538 including taxes.

Rover 95 and Rover 110.

The final members of the series were the 95 and 110. The Rover 95 was a Rover 100 re-geared for economy and offered at the price level of the four-cylinder Rover 80 it replaced. The Rover 110 was a Rover 100 with a more powerful engine. Announced 27 September 1962 these cars represented the end of an era. They were fitted with not alloy but steel door panels to reduce cost. Their very full equipment included electric windscreen washers. Although the Roverdrive automatic had been put to rest, overdrive was standard on the 110. The 95 made do with a higher ratio final drive (3.9:1).  Both cars used the same "" version of the IOE engine. The wider availability of higher octane fuels permitted an increase in the compression ratio to 8.8:1, and the old unit now produced 123 hp (91 kW) in 110 guise, which used a Weslake cylinder head, and 102 hp (76 kW) in the 95.  The Motor magazine road tested, ref 2/64, a Rover 110 on 30 January 1963. This car achieved a mean maximum of 100.0 mph, 0-60 mph in 15.9 seconds and the standing quarter mile in 20.6 seconds. This was the fastest P4 model tested in the series by The Motor. After a successful run of some 15 years, the Rover 95 and Rover 110 were eventually replaced by Rover's wholly new Rover 2000 announced 9 October 1963 but they remained available into 1964.

Gas turbine cars.

The P4 platform was used in Rover's gas turbine programme, most notably as the origin of the JET 1 prototype shown to the public in the United Kingdom and United States in 1950 and subjected to speed tests on the Jabbeke highway in Belgium in 1952. JET 1, a mid-engine two-seat open tourer, was based on the P4 bodyshell. The original JET 1 is on display in the London Science Museum.  Two further prototypes powered by gas turbine were based on the P4. The T2 had a four-door body and its gas turbine under the bonnet at the front of the car. Problems with the T2 caused Rover to abandon the front-engine concept and rebuild the car, redesignated T2A, with the turbine over the rear wheels.

The Rover P4 series is a group of mid-size luxury saloon cars produced by the Rover Company from 1949 until 1964. They were designed by Gordon Bashford.


Club career.

He started off his career at his hometown club, Tirana in 1998. After very few appearances, he was loaned out to Bylis. After making a huge impact, he returned to Tirana to compete for the number 1 shirt. He signed for the Ukrainian club Kryvbas Kryvyi Rih in August 2007. In 2008, Hidi moved to Alki Larnaca for the remainder of the 2008–09 season. Hidi rejoined Kryvbas Kryvyi Rih on a three-year contract for around one million dollars per season on 3 March 2009.  On 6 July 2010, he signed for Dinamo Tirana for the 2010–11 season. On 7 January 2011, Hidi joined Cyprus's Olympiakos Nicosia by inking a contract until the end of the season.  In July 2018, Hidi joined Teuta on a one-year contract, returning in Albanian Superliga after eight years. In November, he was named league's player of the month after some strong performances. He concluded the 2018–19 season by making 33 league appearance, missing only one match, the one against Tirana in April 2019.  In August 2019, Hidi completed a transfer to Bylis, returning in Ballsh for the first time since 2002 when he was on loan. He took squad number 1 for the 2019–20 season. Hidi made his debut on 24 August in the 1–0 away defeat to his former side Teuta. On 1 September, in his third appearance of the season, Hidi scored his first career goal, a penalty in the 3–0 win at Skënderbeu, guiding the team to their first seasonal win. On 15 September, in the first match following the international break, Hidi scored another penalty, this time at home against Kukësi, aiding Byis to achieve a 2–1 comeback win which lifted them in 4th place in championship. His first goal in Albanian Cup came on 12 February 2020 in the second leg of competition's second round against Laçi, helping Bylis advance to quarter-finals 4–3 on aggregate.

International career.

Hidi received his first senior international call-up in May 2005 for the friendly match versus Poland by German coach Hans-Peter Briegel who was impressed by Hidi's performances in the Albanian Superliga with his club at the time Tirana. He earned his first cap in that match, but things could not have started any worse for him as Poland scored in under 2 minutes with Maciej Żurawski. Hidi's second appearance for Albania came later that year, on 17 August against Azerbaijan at Qemal Stafa Stadium; he started again and conceded another early goal, but this time the team bounced back and won 2–1 in front of around 7,300 Albanian fans.

Personal life.

In 2017, Hidi begun the application for Cypriot passport.

Isli Hidi (born 15 October 1980) is an Albanian professional footballer who plays as a goalkeeper, most recently for Bylis in the Albanian Superliga and the Albanian national team. Hidi has won 11 official titles, being one of Albanian footballers with most honours in history.


The problem addressed by Semantic Web Services.

The mainstream XML standards for interoperation of web services specify only syntactic interoperability, not the semantic meaning of messages. For example, Web Services Description Language (WSDL) can specify the operations available through a web service and the structure of data sent and received but cannot specify semantic meaning of the data or semantic constraints on the data. This requires programmers to reach specific agreements on the interaction of web services and makes automatic web service composition difficult.  Semantic web services are built around universal standards for the interchange of semantic data, which makes it easy for programmers to combine data from different sources and services without losing meaning. Web services can be activated "behind the scenes" when a web browser makes a request to a web server, which then uses various web services to construct a more sophisticated reply than it would have been able to do on its own. Semantic web services can also be used by automatic programs that run without any connection to a web browser.  A semantic-web-services platform that uses OWL (Web Ontology Language) to allow data and service providers to semantically describe their resources using third-party ontologies is SSWAP: Simple Semantic Web Architecture and Protocol. SSWAP establishes a lightweight protocol (few OWL classes and predicates; see the SSWAP Protocol) and the concept of a "canonical graph" to enable providers to logically describe a service. A service is essentially a transformation of some, possibly null, input (or subject) to some, possibly null, output (or object). Services are semantically discoverable based on their subsumption hierarchies as well as their input and output data types.  SADI (Semantic Automated Discovery and Integration) is a semantic-web-service initiative that consists of a set of design-practices for semantic-web-service publishing that minimizes the use of non-standard protocols and message structures. SADI Services natively consume data in RDF Resource Description Framework format, where input and output data must be instances of (OWL Individuals of) input and output Classes defined in OWL-DL. Unlike canonical Web Services, SADI Services do not use the SOAP messaging protocol, and unlike SSWAP, SADI services have no project-specific messaging scaffold; services are invoked by passing RDF instance data to the Service endpoint through HTTP POST, and multiplexing is achieved by sending more than one OWL Individual in the HTTP POST invocation. SADI imposes a single constraint on the behavior of the Service: that the URI of the output individual must be the same as the URI of the corresponding input individual. In practice, this results in Services that create semantic linkages between the input and output of the service. Thus, chaining SADI services together into a workflow results in an uninterrupted Linked Data graph.

Choreography vs. orchestration.

"Choreography" is concerned with describing the external visible behavior of services, as a set of message exchanges optionally following a Message Exchange Pattern (MEP), from the functionality consumer point of view.  "Orchestration" deals with describing how a number of services, two or more, cooperate and communicate with the aim of achieving a common goal.

A semantic web service, like conventional web services, is the server end of a client–server system for machine-to-machine interaction via the World Wide Web. Semantic services are a component of the semantic web because they use markup which makes data machine-readable in a detailed and sophisticated way (as compared with human-readable HTML which is usually not easily "understood" by computer programs).


Taxonomy.

The genus was introduced in 1876 by Tamerlan Thorell. Subsequent research subdivided the genus into five subgenera, however recent studies doubt on these subgenera to represent natural groups.

Diversity.

Currently, 21 species are recognized within this genus:

Doubtful species.

"Pandinus boschisi" Caporiacco, 1937, known only from one, presumably lost specimen from Somalia, is considered a "nomen dubium".

General characteristics.

Members of "Pandinus" are generally large scorpions (about 120–200 mm total length), which are dark to black colored, sometimes with paler metasoma and legs. The pedipalp pincers are massive, while the metasoma is proportionally thin with a small vesicle and stinger (aculeus). They possess a stridulatory organ, composed of a rough area on the first segment (coxa) of the pedipalps and a'scraper' made of bristles on the first segment of their first pair of walking legs. Scraping these bristles on the rough zone produces a scratching sound. Genera of the subfamily Scorpioninae are extremely similar to each other and "Pandinus" is especially close to the Southeast Asian genus "Heterometrus". They differ mainly in details of the stridulatory organ and sensory bristles (trichobothria).

Toxicity.

As in other Scorpionidae, the venom of "Pandinus" species is rather mild, human fatalities are unknown. Symptoms are mostly restricted to local pain, described similar to those of a bee sting. At least "P. imperator" rarely stings at all, and often prefers to use its massive pincers for prey capture and even for defense. The defensive behavior of the other species is not yet studied in detail.

Habitat.

Most species live in humid tropical low-land regions. They occur in rain forest, gallery forest near rivers and other woodlands aside of savannah habitats. Arabian species also occur in semiarid climates. Soft, loamy soils seem to be preferred by most species, but ecology is only well known for the forest-living "P. imperator".

Conservational status.

Three species of "Pandinus" ("P. imperator", "P. dictator", and "P. gambiensis") are the only scorpions listed by the CITES Appendix II since 1995, due to overexploitation for pet trade from the wild. This total is now four species since, in 2017, the CITES taxonomy of "P. imperator" was split into "P. imperator" and "P. roeseli". CITES export quotas have been issued for "P. imperator" by several countries in West Africa (including Benin, Togo, Niger, and Chad).<br> The CITES listing has been conceptually criticized for protecting three species, of which only one ("P. imperator") is frequently exported for international pet trade. However, several other, unprotected species are also harvested for export, especially "P. cavimanus" and "P. viatoris" in Tanzania. Even in countries with effective quotas, the origin of traded specimens either from farms or from the wild is hardly traceable. Beside of overharvesting, the species are most endangered by habitat destruction due to deforestation. Traded specimens are sometimes labelled ""Pandinus africanus"". This name is an invalid synonym for "P. imperator" and apparently used to avoid CITES regulations for this species. However, other - unlisted - species were also traded under this name.

In captivity.

The large size, its docile and gregarious behaviour, partly diurnal activity and mild venom make "P. imperator" the most popular pet scorpion. After listing of the species in CITES, commercial scorpion farms have been established in several West African countries. A few other species, especially "P. cavimanus", are also frequently kept in captivity.

Pandinus is a genus of large scorpions belonging to the family Scorpionidae. It contains one of the most popular pet scorpions, the emperor scorpion ("P. imperator"). The genus is distributed widely across tropical Africa and the southeastern Arabian Peninsula (Yemen and Saudi Arabia).


Government.

Bo District has its own directly elected local government called District Council and is where executive and lesgislative authority is vested at local level within Bo District. The Bo District Council is Headed by a council chairman, who is an elected official and is responsible for the general management of the district. The current council Chairman of Bo District is Joseph Munda Bindi of the Sierra Leone People's Party (SLPP), following his election victory in the 2018 Sierra Leone local election.  The city of Bo also has its own directly elected city council headed by a mayor. The current mayor of Bo is Harold Logie Tucker, he is a member of the opposition Sierra Leone People's Party (SLPP). Bo District is a stronghold of the ruling Sierra Leone People's Party.

Members of Parliament of Sierra Leone from Bo District.

Bo District currently has twelve Representatives in the Parliament of Sierra Leone, of which eleven members were elected for a 5-year term in the 2007 general elections. The district is a stronghold of the opposition Sierra Leone People's Party (SLPP). The following is a list of Representatives and affiliations:

Demographics of Bo District.

Ethnicity.

The population of Bo District is ethnically and culturally diverse, particularly in the city of Bo, Sierra Leone's second largest city. The Mende people form the largest ethnic group in Bo District at over 60 percent of the population.

Economy.

With Bo being the second largest city in Sierra Leone, trading, gold and diamond mining are major economic activities for the district; as well as agricultural production of rice growing, and coffee, cacao and oil palm.

Education.

Bo District is home to 385 Primary Schools and 40 Secondary Schools. Bo Government Secondary School, commonly called Bo School is among the 40 secondary schools in Bo District. The school was founded in 1906 by Leslie Probyn to educate the children of Bo District. The school has a long history of developing the elite of Sierra Leone, especially the country's politicians.

Recovery after Civil War.

Bo District suffered badly at the hands of rebel forces during 1994/1995, and many major towns were almost entirely destroyed (Tikonko and Bumpe, for example). However, since the ousting of the Junta in early 1998, Bo District has remained secure, due mainly to the strong presence of the Civil Defence Forces. As such, rather than suffering from displacement, Bo district has been the recipient of displaced persons from less secure parts of the country.  Although aid agencies have had uninterrupted access to the district for five years because of its relative stability, most of the recovery efforts were concentrated in Bo Town leaving out the 8 sections in Kakua chiefdom as well as all the other 14 chiefdoms in the district.  The major recovery needs according to sectoral priorities are as follows: Road rehabilitation, Education, Water and Sanitation, Health, Agriculture, Restoration of Local Government Structures and Shelter.

Administrative divisions.

Chiefdoms.

The district is made up of fifteen chiefdoms as the third level of administrative subdivision.

Bo District is a district in the Southern Province of Sierra Leone. It is one of the sixteen Districts of Sierra Leone. Bo District is the fourth most populous District in Sierra Leone. Its capital and largest city is the city of Bo, which is the third most populous city in Sierra Leone. other major towns in the district include Baoma, Bumpeh, Serabu, Sumbuya, Baiima and Yele.


Early life and career.

Hartmann was born on 11 December 1902 in Silstedt near Wernigerode in the Province of Saxony, a province of the Kingdom of Prussia in the German Empire. He was the third child of Albert Hartmann, an evangelic pastor in Wernigerode, and Helene Hartmann, née Wernicke. Hartmann had one older brother, Rudolf, and an older sister, Edith. From 1909 to 1914, he attended the "Volksschule", a primary school, in Silstedt and later the "Gymnasium", a secondary school, in the district of Magdeburg.  On 1 April 1914, Hartmann joined the "Königlich Preußischen Kadettenkorps" (Royal Prussian Cadet Corps) in Oranienstein near Diez. He initially served in the "Vorkorps" (pre corps) before he transferred to the "Hauptkadettenanstalt" (Main Military Academy) in Berlin-Lichterfelde on 1 April 1917. There he graduated with his "Abitur" (diploma) in 1921. Following his graduation he began his naval career with the "Reichsmarine" of the Weimar Republic on 1 April 1921 as a member of "Crew 21" (the incoming class of 1921).  Until 30 September 1925, he underwent a number of military and naval training courses. It began with basic military training (1 April – 30 September 1921) in Stralsund at the Baltic Sea and weapons courses at the Naval Academy at Mürwik. Hartmann was then transferred to the (1 October 1921 – April 1922) for onboard training and then to the training ship "Niobe" (April – 30 June 1922). During this timeframe, he advanced in rank to "Fähnrich zur See" (officer cadet) on 1 April 1923 and to "Oberfähnrich zur See" (Senior Ensign) on 4 April 1925.  He went on to serve as commander of the torpedo boats and, before transferring to the U-boat arm in 1935. During the Spanish civil war, he commanded that patrolled Spanish waters during the Civil War in 1937–38 with Günther Prien as his first watch officer.

World War II.

From January–May 1940 Hartmann was commander of both and "2nd U-boat Flotilla", but directing U-boats while at sea proved inefficient, and the Befehlshaber der U-Boote ("U-boat High Command") decided henceforth to direct the U-boats from land. After three patrols, and sinking 19 ships totalling, Hartmann received the Knight's Cross of the Iron Cross. His senior officers on his four patrols on " U-37" were future Knight's Cross winners, first watch officer "Oberleutnant zur See" Ernst Bauer (two patrols) and later "Oberleutnant zur See" Nicolai Clausen (two patrols), second watch officer "Leutnant zur See" Gustav Poel and chief engineer "Oberleutnant" (Ing.) Gerd Suhren.

First patrol.

Hartmann's first patrol (19 August 1939 – 15 September 1939) on "U-37" left Wilhelmshaven almost two weeks before the outbreak of World War II on Friday 1 September 1939 when German forces invaded Poland. Commander of "U-37" on this patrol was "Kapitänleutnant" Heinrich Schuch.

Ashore.

Hartmann then moved to the BdU as a staff officer, and in November 1940 became commander of the 2nd ULD (U-boat Training Division). A year later he took command of the "27th U-boat Flotilla" in Gotenhafen. In November 1942 he took command of the large Type IXD for a patrol to the Indian Ocean lasting 200 days, the third longest patrol ever undertaken, and sank 7 ships totalling. Chief engineer was Johann-Friedrich Wessels who received the Knight's Cross for his services on this patrol. In 1944 Hartmann became "Führer der Unterseeboote Mittelmeer" ("Commander of U-boats in the Mediterranean") and in this post received the Knight's Cross with Oak Leaves.

Bundesmarine and later life.

After the war he joined the "Bundesmarine" on 1 July 1956, commanding the 1. "Schiffsstammregiment" (1st Naval training regiment) in Glückstadt, retiring on 1 April 1962. He died on 26 April 1963 in Usseln/Waldeck of pulmonary embolism. He was buried in a family grave in Glückstadt.

Summary of career.

Ships attacked.

As commander of and Werner Hartmann is credited with the sinking of 26 ships for a total of.

Werner Hartmann (11 December 1902 – 26 April 1963) was a German U-boat commander in World War II. He was credited with sinking 26 ships, amounting to over sunk, purportedly making him the 25th most successful U-boat commander of the war. He was a recipient of the Knight's Cross of the Iron Cross with Oak Leaves of Nazi Germany.


Biography.

Olweus was born on April 18, 1931, in Nässjö, Sweden. In 1969, he earned a PhD from Umeå University in Sweden, with a dissertation on aggressive behaviour among young boys. He joined the faculty at the University of Bergen, in Norway, in 1970. He was a professor of psychology from 1970 to 1995, and has been a research professor of psychology since 1996.  Olweus was a fellow at the Center for Advanced Study in the Behavioral Sciences at Stanford University from 1986 to 1987. He served as president of the International Society for Research on Aggression from 1995 to 1996.

Research.

Bullying.

In the 1970s, Olweus conducted a systematic study of bullying among children. This work was published in Scandinavia in 1973, and in the United States in 1978 (as the book, "Aggression in the Schools: Bullies and Whipping Boys"); it is generally considered to be the first scientific study of bullying in the world. Olweus defined bullying as unwanted aggressive behaviour that is repeated over time and involves an imbalance of power or strength.  Olweus's 1993 book, "Bullying at School: What We Know and What We Can Do", has been translated into 20 languages. He published the first systematic study of bullying perpetrated by teachers towards students, published in 1996.

Olweus Bullying Prevention Program.

In the 1980s, Olweus conducted the first systematic study of a bullying intervention program. The success of the program led to a government-led initiative to implement the intervention (which would become known as the Olweus Bullying Prevention Program [OBPP]) throughout all Norwegian elementary and junior high schools. The program aims to reduce bullying through restructuring the school classroom and rewarding positive behaviours.  The OBPP has been systematically evaluated in a number of large-scale studies in Norway that have included more than 30,000 students. Studies have indicated a reduction in reports of being bullied and bullying others of about 35 to 45%, among students involved in the program.  One study, conducted by Olweus and Sue Limber of Clemson University in South Carolina, evaluated the effectiveness of the program in U.S. schools, including nearly 70,000 students, over the course of three years. The study found reductions in students' reports of being bullied and bullying others, as well as increases in students' expressions of empathy.  In addition to the Norway and the U.S., the OBPP has been implemented in Iceland, Sweden, and Lithuania, and is being piloted in Mexico, Brazil, and Germany.

Awards and honours.

In 2002, Olweus received the Nordic Public Health Prize from the Nordic Council. In 2003, Olweus was given the Award for Distinguished Contributions to Public Policy for Children by the Society for Research in Child Development.  Olweus received the 2011 American Psychological Association (APA) Award for Distinguished Contributions to the International Advancement of Psychology. In 2012, he received the APA Award for Distinguished Contributions to Research in Public Policy. In 2018, he was awarded the Christie Prize from the University of Bergen.

Dan Olweus (born April 18, 1931) is a Swedish-Norwegian psychologist. He is a research professor of psychology at the University of Bergen, Norway. Olweus has been widely recognized as a pioneer of research on bullying.


History.

Origins.

Bob Albrecht edited an eccentric newspaper about computer games programmed in the BASIC computer language, with the same name as the tiny nonprofit educational corporation that he had founded, "People's Computer Company" (PCC). Dennis Allison was a longtime computer consultant on the San Francisco Peninsula and sometime instructor at Stanford University. The "Dobbs" title was based on a mashup of the first letters of their names: Dennis and Bob.

First issues.

In the first three quarterly issues of the PCC newspaper published in 1975, Albrecht had published articles written by Allison, describing how to design and implement a stripped-down version of an interpreter for the BASIC language, with limited features to be easier to implement. He called it Tiny BASIC. At the end of the final part, Allison asked computer hobbyists who implemented it to send their implementations to PCC, and they would circulate copies of any implementations to anyone who sent a self-addressed stamped envelope. Allison said, "Let us stand on each others' shoulders; not each others' toes."  The journal was originally intended to be a three-issue xerographed publication. Titled dr. dobb's journal of Tiny BASIC Calisthenics & Orthodontia (with the subtitle "Running Light Without Overbyte") it was created to distribute the implementations of Tiny BASIC. The original title was created by Eric Bakalinsky, who did occasional paste-up work for PCC. "Dobb's" was a contraction of "Dennis" and "Bob". It was at a time when computer memory was very expensive, so compact coding was important. Microcomputer hobbyists needed to avoid using too many bytes of memory.  After the first photocopies were mailed to those who had sent stamped addressed envelopes, PCC was flooded with requests that the publication become an ongoing periodical devoted to general microcomputer software.  PCC agreed, and hired Jim Warren as its first editor. He immediately changed the title to Dr. Dobb's Journal of Computer Calisthenics & Orthodontia prior to publishing the first issue in January 1976.

Early years.

Jim Warren was DDJ's editor for about a year and a half. While he went on to make a splash with his series of West Coast Computer Faires, subsequent DDJ editors like Marlin Ouverson, Hank Harrison, Michael Swaine and Jonathan Erickson appear to have focused on the journalistic and social aspects of the young but growing microcomputer industry. Eventually PCC, the non-profit corporation, sold DDJ to a commercial publisher.  The newsletter's content was originally pure enthusiast material. Initial interest circled around the Tiny BASIC interpreter, but Warren broadened that to include a variety of other programming topics, as well as a strong consumer bias, especially needed in the chaotic early days of microcomputing. All of the content came from volunteer contributors, with Steve Wozniak as one of the better known of them. Other contributors included Jef Raskin, later credited as a leader in the Macintosh development; Hal Hardenberg, the originator of DTACK Grounded an early newsletter for Motorola 68000 based software and hardware; and Gary Kildall, who had created CP/M, the first disk operating system for microcomputers which was not married to proprietary hardware.  Computer program source code published during the early years include:  The March 1985 issue "10(3)" printed Richard Stallman's "GNU Manifesto" a call for participation in the then-new free software movement.

Discontinuation of printed edition.

In later years, the magazine received contributions from developers all over the world working in application development and embedded systems across most programming languages and platforms. The magazine's focus became more professional. Columnists included Michael Swaine, Allen Holub and Verity Stob, the pseudonymous British programmer.  The title was later shortened to "Dr. Dobb's Journal", then changed to "Dr. Dobb's Journal of Software Tools" as it became more popular. The magazine later reverted to "Dr. Dobb's Journal" with the selling line, ""The World of Software Development"", with the abbreviation DDJ also used for the corresponding website. In January 2009 Jonathan Erickson, the editor-in-chief, announced the magazine would cease monthly print publication, become a section of "InformationWeek" called "Dr Dobb's Report.", a website and monthly digital PDF edition.

Later history.

The primary Dr. Dobb's content streams at the end were the Dr. Dobb's website, "Dr. Dobb's Journal" (the monthly PDF magazine, which had different content from the website) and a weekly newsletter, "Dr. Dobb's Update". In addition, Dr. Dobb's continued to run the Jolt Awards and, since 1995, the Dr. Dobb's Excellence in Programming Award. Regular bloggers include Scott Ambler, Walter Bright, Andrew Koenig, and Al Williams. Adrian Bridgwater edited the news section beginning in 2010.

End.

On December 16, 2014, an article by editor-in-chief Andrew Binstock announced that "Dr. Dobb's" would cease publication of new articles at the end of 2014. Archived articles are still available online. While no longer being distributed, Dr. Dobb's is now widely considered as an important and influential source for the history of the PC industry.

Dr. Dobb's Journal (DDJ) was a monthly magazine published in the United States by UBM Technology Group, part of UBM. It covered topics aimed at computer programmers. When launched in 1976, DDJ was the first regular periodical focused on microcomputer software, rather than hardware. In its last years of publication, it was distributed as a PDF monthly, although the principal delivery of "Dr. Dobb's" content was through the magazine's website. Publication ceased at the end of 2014, with the archived website continuing to be available online.


Motivation.

Since the 1960s computers have been shared between users. Especially in the early days of computing when computers were extremely expensive the usual paradigm was a central mainframe computer connected to numerous terminals. With the advent of personal computing this paradigm has been largely replaced by personal computers (or one computer per user).  Multiseat setups are a return to this multiuser paradigm but based around a PC which supports a number of zero-clients usually consisting of a terminal per user (screen, keyboard, mouse).  In some situations such multiseat are cost-effective because it is not necessary to buy separate motherboards, microprocessors, RAM, hard disks and other components for each user. For example, buying one high speed CPU usually costs less than buying several slower CPUs.

History.

In the 1970s, it was very commonplace to connect multiple computer terminals to a single mainframe computer, even graphical terminals. Early terminals were connected with RS-232 type serial connections, either directly, or through modems. With the advent of Internet Protocol based networking, it became possible for multiple users to log into a host using telnet or – for a graphic environment – an X Window System "server". These systems would retain a physically secure "root console" for system administration and direct access to the host machine.  Support for multiple consoles in a PC running the X interface was implemented in 2001 by Miguel Freitas, using the Linux operating system and the X11 graphical system (at the time maintained by XFree86). This was done using a patch in the display server to execute several instances of X at the same time such that each one captures specific mouse and keyboard events and the graphical content. This method received the name of multiseat or multiterminal.  In 2002 a Canadian company, Userful Corporation, released Userful Multiplier, a multiseat Linux software solution that enables up to 10 users to simultaneously share one computer. Earlier they worked on a kernel-based approach to a multi-station platform computer, but abandoned the idea due to a problem with multiple video card support.  Other solutions appeared in 2003, such Svetoslav Slavtchev, Aivils Stoss and James Simmons worked, with the evdev and Faketty approach modifying the kernel Linux and letting more than one user independently use the same machine. In that time, the Linux Console Project also proposed an idea to use multiple independent consoles and then multiple independent keyboards and mice in a project called "Backstreet Ruby". Backstreet Ruby is a kernel patch for the Linux kernel. It is a back port to Linux-2.4 of the Ruby kernel tree. The aim of the Linux Console developers is to enhance and reorganize the input, the console and the framebuffer subsystems in the Linux kernel, so they can work independent from each other and to allow multi-desktop operation. The Backstreet Ruby idea was never finished.  In 2005, the C3SL team (Center for Scientific Computing and Free Software), from the Federal University of Parana in Brazil, created a solution based on nested display servers, such as Xnest and Xephyr. With this solution, each nested display server runs in each screen of a host display server (e.g. Xorg) and a modification to the nested servers let each one exclusively acquire its mouse and keyboard. In 2008, the C3SL group released the Multiseat Display Manager (MDM) to ease the process of installation and configuration of a multiseat box. This group, also in 2008, conceived a live-CD for test purposes.  Automatic multiseat with USB docking stations is a feature of Fedora 17.

Requirements.

Hardware requirements.

Each monitor will need to be connected to a graphics output from a video card. For example, to make a "four-head" (four users), would require four monitors, four keyboards, four mice and two dual or one quad output video card. USB keyboards and mice are typically recommended instead of PS/2 connections, as they can be connected to a USB hub. Additional devices and peripherals such as cameras, flash storage drives, card readers and touch screens could also be assigned to each seat. An alternative to multiple physical video cards and connections is DisplayLink over USB.

Software requirements.

GNU/Linux.

The VT system in the Linux kernel dates back to 1993 and does not understand the concept of multiple "seats". kmscon and systemd-consoled do.  There are different solutions to set up a multiseat and others are constantly being developed. The X.Org Foundation maintains a wiki page with the latest news concerning the solutions. Currently the most pointed solutions by X.Org's wiki are the solutions using either multiple Xephyr servers with deprecated evdev support over a host Xorg, or run several instances of Xorg using multiple video devices. It is quite easy to configure popular distributions such as Ubuntu to provide multiseat environments as documented on the Ubuntu MultiseatX wiki page.  The Multi-seat Display Manager automseat tool is an open source tool which helps to automatize the process of installation and configuration. Users that want to try multiseat are encouraged to try such a tool and avoid the old and hard way to set it up through these howtos (, ), as stated by foundation's wiki page. On the other hand, MDM suffers from lack of updates and releases beyond the initial announcement. Another open source tool that aims to help simplify the creation of multiseat, mainly for the Ubuntu distribution, is the Bicefalo wizard.  Userful offers a commercially supported multiseat Linux solution called Userful Multiplier. It enables up to 10 users to simultaneously share one computer. It works with most graphics cards supported by X.Org/XFree86 as well as USB multiseat devices. It is available in 64-bit and 32-bit packages in both RPM and DEB formats, and has been tested on most major distributions, including Debian, Fedora, Mandriva Linux, SLED, SuSE and Ubuntu. A free two-user version of Userful Multiplier software for personal or trial use is available from their website.

Microsoft Windows.

For Windows 2000, XP and Vista operating systems, there are several commercial products to implement multiseat configurations for two or more seats.  An operating system designed specifically for multiseat setups entitled Windows MultiPoint Server was announced on February 24, 2010. It uses Remote Desktop (Terminal Services) technologies in Windows Server 2008 R2 to provide multiseat functionality. This functionality was incorporated into Windows Server proper as of Windows Server 2016 in a new server role entitled MultiPoint Services, but this server role was removed in Windows Server 2019 owing to Microsoft ceasing development of the service in 2018.

Virtualization-based setup.

Instead of relying on operating system support for multiseat configuration, a hypervisor can be configured to run multiple virtual machines, each configured to interface one connected seat by I/O virtualization methods. Input devices can be attached to the virtual machines through USB Redirection, and entire GPUs can be attached through Intel VT-d.  The YouTube channel "LinusTechTips" has demonstrated virtualization-based 2-seat and 7-seat systems with UnRAID as the host operating system. Each seat has exclusive control of one of the Windows guest operating systems running on the host. There is a dedicated high-end graphics card for each guest, which it takes full advantage of via the use of VT-d, making the system capable of hosting demanding video game sessions at full quality simultaneously on all seats.

Case studies.

World's largest multiseat computer deployment.

In February, 2009, The Brazil Ministry of Education committed to deploy 350,000 Linux-based multiseat computing stations in more than 45,000 rural and urban schools across the country. The chosen companies to implement this project were the Canadian multiseat Linux software company Userful Corporation, and its Brazilian IT partner ThinNetworks.

Paraná Digital project.

One of multiterminal's successful cases is happening at Paraná Digital project. It is creating multiterminal laboratories on 2000 public schools of the state of Paraná (Brazil). More than 1.5 million users will benefit from the 40,000 terminals when the project is finished. The laboratories have four-head multiterminals running Debian. The cost of all the hardware is 50% less than the normal price, and there is absolutely no cost with software. This project developer is C3SL (Center for Scientific Computing and Free Software).

Michigan State University research in Tanzania.

Since 2008, electrical and computer engineering students from Michigan State University have installed multiterminal systems with internet access in three schools in Mto wa Mbu, Tanzania. The purpose of the project is to study the impact of having computer systems with internet access in an education system that cannot afford other educational resources such as books. The computer systems run Ubuntu 8.04 32-bit and utilize the open source Multiseat Display Manager created by C3SL. The research will eventually be used to present to government officials of third world countries in effort to showcase the positive impact of having cost-effective computing systems in schools. The project is sponsored by George and Vickie Rock and the Dow Chemical Company.

A multiseat, multi-station or multiterminal configuration is a single computer which supports multiple independent local users at the same time.


History.

The original Vereinigte Deutsche Metallwerke AG (VDM) was founded in 1930 by the takeover of "Heddernheimer Kupferwerk and Süddeutsche Kabelwerk AG" in Frankfurt by "Berg-Heckmann-Selve AG" in Altena. The merger took place on the initiative of Metallgesellschaft, which was the main shareholder of Heddernheimer Kupferwerke since 1893 and also took over the majority of the new corporate group. The global economic crisis had forced a consolidation of previously competing companies.  The new company had a share capital of 30 million Reichsmark and had branches and manufacturing facilities in Heddernheim, Gustavsburg, Mannheim, Nuremberg, Cologne and in Altena, Werdohl and Duisburg. The group's companies remained independent under their previous name (e. g. Heddernheimer Kupferwerk GmbH), but the production program was redistributed by material group to the individual plants. In March 1934, VDM moved its headquarters to Frankfurt am Main. The incipient rearmament of the Wehrmacht skyrocketed the demand for light metal products. By 1939, the number of employees at VDM rose to 21,000, mainly due to the production of variable pitch propellers for aircraft of the Luftwaffe.

After 1945.

Because of the great importance of the VDM for the war economy, almost all buildings and factories were heavily destroyed in the air raids on Frankfurt am Main during the Second World War. At the end of the war, the production collapsed completely, all works were shut down at the direction of the Allies and partly dismantled. It was not until 1946, under the leadership of Wilhelm Kirmser, that the gradual reconstruction and transition to civilian production began.  In the early 1950s, VDM became the world's largest manufacturer and distributor of raw, semi-finished and finished non-ferrous metals and alloys. The upswing reached its peak in the financial year 1960/61. Thereafter, the company continuously lost market share.

The crisis years after 1966.

Already for 1966/67 no dividend could be paid to shareholders. A major cause of the difficulties was the fragmented corporate structure of six separate companies, which did not allow a consistent strategy and investment.  In 1969, the plant in Cologne was shut down and the remaining works were combined into seven business units:  Despite the restructuring and some acquisitions in the 1970s, sales continued to decline. The company reacted with rationalization measures, a reorientation of the production strategy, the sale of individual company shares and the closure of unprofitable production units and plants. This reduced the number of employees from 14,200 (1970) to 6,700 in 1979. After a dramatic deterioration of the results in the financial year 1980/81, the parent plant in Frankfurt-Heddernheim was closed after 129 years on 31 March 1982.  At this point in time, only the plants of the business area nickel (Altena, Unna and Werdohl) were still productive. In the following years, VDM gradually separated from all remaining production facilities and changed its name to MG Vermögensverwaltung AG in 1988.

Spin-off of the nickel division 1988.

In 1988 the German steelmaker Krupp took over one third, one year later 100 percent of the shares in the "VDM Nickel Technologie AG". This division was formed from the merger of the Werdohl and Altena plants into the business area nickel in 1974. In the following years Krupp VDM - as the company was called - initially took over "Precision Rolled Products (PRP)" with production sites in New Jersey and Nevada and, on 1 October 2009, the activities of the sister company ThyssenKrupp Titanium. From then on, VDM became part of the ThyssenKrupp stainless steel division and operated under the name "ThyssenKrupp VDM" until 2012.  Following the sale of the stainless steel division of ThyssenKrupp to Outokumpu in December 2012, VDM temporarily traded under the name Outokumpu VDM. At the end of November 2013 it was announced that VDM would be re-integrated into the ThyssenKrupp Group. Since 1 March 2014, VDM had once again been part of the ThyssenKrupp Group and has since been trading under the independent name of VDM Metals.  In April 2015, ThyssenKrupp announced the sale of the VDM Group to the financial investor Lindsay Goldberg. On 1 August 2015, the sale was completed. In November 2019, the Spanish stainless steel producer Acerinox announced the signing of a share-purchase-agreement to acquire VDM Metals.

Inventions and material developments.

Alloy C-264.

Alloy C-264 is a superalloy developed by VDM Metals and launched in 2018. In addition to the alloying element nickel, the alloy contains 25 percent chromium, 20 percent cobalt, about 5.5 percent molybdenum and 1.1 percent aluminum and 1.7 percent titanium. Various tests have shown that the material in the solution-annealed and hardened condition achieves higher hardness values and lower creep rates than, for example, Alloy C-263 (material number 2.4650, UNS N07263). The application temperature is up to 900 degrees Celsius.

Alloy 699 XA.

In June 2018, a nickel base alloy with 29 percent chromium and 2 percent aluminum was introduced, which is characterized in particular by its metal dusting resistance. The material has the material number 2.4842 or UNS N06699.

VDM Metals Group (formerly Vereinigte Deutsche Metallwerke) based in Werdohl, Germany, is a manufacturer of corrosion-resistant, heat-resistant and high-temperature nickel alloys, cobalt and zirconium alloys as well as high-alloyed special stainless steels. These materials are used in the chemical process industry, the oil and gas industry, aerospace, automotive and electronics / electrical engineering. VDM Metals operates production sites in Germany (Altena, Siegen, Unna and Werdohl) and the United States (Florham Park, NJ, and Reno, NV). The company employs about 2,000 people worldwide.


Biography.

Known for its Afrocentrism and militant activism as member of the Blackwatch movement, X Clan soon gained fame for the controversy its music aroused, though commercial success was sporadic. X Clan's debut was "To the East, Blackwards" (1990), followed by "Xodus" (1992) and a temporary break-up. Both albums peaked at #11 on Billboard's Top R&B/Hip-Hop Albums chart in the United States.  Other artists who were affiliated with X Clan and Blackwatch include Isis, Queen Mother Rage, and YZ. X Clan's affiliates released a string of titles throughout the early 1990s: Professor X released a solo album titled "Years of the 9, on the Blackhand Side" in 1991 and a second solo album titled "Puss N' Boots: The Struggle Continues" in 1993; Queen Mother Rage released "Vanglorious Law" in 1991 ("vanglorious" is a word that the group made up—not to be confused with “vainglorious”); Isis released "Rebel Soul" in 1990; and YZ released his debut "Sons of The Father" (noted for the song "Thinking of a Master Plan"), in 1989, followed by "The Ghetto's Been Good to Me" (which included his modest hit "Return of the Holy One") in 1993. YZ became affiliated with the group after releasing his first album, and that Isis is also the MC known as Linque Ayoung, who at one point was a member of the Wu-Tang Clan-affiliated group Deadly Venoms.

Later projects.

In 1994 Brother J formed a new group, Dark Sun Riders, that released the full-length "Seeds of Evolution" in 1996. In 1995, long-time group member Sugar Shaft died from complications of AIDS. Brother J was an early and valued member of the worldwide Hip Hop organization called Ill Crew Universal. X Clan reunited in the late 1990s but did not release any new material. Brother J assembled a new crew that he calls X Clan Millennium Cipher and released a vinyl single for "The One/Blackwards Row" in 2004. Professor X died from complications of spinal meningitis on March 17, 2006.  A new X Clan album, titled "Return from Mecca" (originally titled "The Trinity"), was released in 2007, featuring Damian "Jr Gong" Marley, Chali 2na of Jurassic 5, RBX, KRS-One, Daddy X of Kottonmouth Kings, and Jacoby Shaddix, lead vocalist of the rock band Papa Roach. Also, Tech N9ne is featured on a hidden bonus track titled "Respect."  X Clan opened for Insane Clown Posse's Tempest Tour and, in January 2009, released an album titled "Mainstream Outlawz".

X Clan (formerly stylized as XCLAN and often incorrectly spelled X-Clan) is a hip hop group from Brooklyn, New York, originally consisting of Grand Verbalizer Funkin' Lesson Brother J, Professor X the Overseer, Paradise the Architect, and Sugar Shaft the Rhythm Provider. The current incarnation of the group features leader Brother J, Master China, Kumu, "Ultraman" Ra Hanna, ACL, Lord Cza, DJ Fat Jack and Zulu.