omniomni/omni-engineering huggingface dataset:
Cwm Dyli. Cwm Dyli is the location of a hydro-electric power station on the southern flank of the Snowdon range in North Wales. At the time it was built, it was the largest hydro-electric power station in the United Kingdom. It is Britain's oldest power station, and is believed to be one of the oldest Grid-connected hydro-electric stations in the world.

History 
The station was built in 1905 by the Porthmadog, Beddgelert and South Snowdon Railway company, backed by North Wales Power and Traction Co Ltd to supply electricity to its own electric railway and connected slate quarries and mines. The railway was planned to run through the same valley as the power station and be fed with an electrical feeder, but the enterprise ran short of funds and the attempt was abandoned. The company was renamed the North Wales Power Company Limited.  

In August 1906, power from Cwm Dyli was used to power the Oakeley Quarry in Blaenau Ffestiniog carried over the Crimea Pass by a long overhead transmission line at 10,000 volts. It also supplied Dinorwic and Pen-yr-Orsedd quarries. Cwm Dyli was claimed to be the largest electricity generating plant of its kind in Great Britain at the time.

Electricity produced here was also used to power the Carnarvon Long Wave Wireless Telegraph transmitting station built by Marconi in 1913–14 near Waunfawr.

Supplying power directly to the National Grid, it is Britain's oldest power station, and is believed to be one of the oldest Grid-connected hydro-electric stations in the world.  It was first commissioned in 1906 and has been in fairly continuous operation since then, although it was closed for upgrading in 1990.  A single turbine now produces up to 9.8 megawatts (MW).

Known locally as the "Chapel in the valley", on account of its exterior design, it employed 13 men.  Today, however, it is controlled remotely from Dolgarrog in the Conwy valley.

Water for the site primarily comes from Llyn Llydaw, some 320 metres above the power station, where rainfall is very high. The water is carried from the lake through a tunnel and  two 30-inch (0.762 m) diameter,  long pipelines.

The pipeline featured in the James Bond film The World Is Not Enough.

Technical details 
The generating equipment at Cwm Dyli up to 1989 comprised:

 2 × Ganz Pelton wheels
 2 × Boving Pelton wheels, together these aggregated a capacity of 900 horse power (6.619 MW)

The four wheels drove:

 1 × 1 MW Bruce Peebles alternator
 1 × 1.5 MW Bruce Peebles alternator
 1 × 3 MW Bruce Peebles alternator

The total electricity generating capacity was 6.5 MW, at 10 kV.

The following graph shows the annual electricity output in MWh from Cwm Dyli between 1921 and 1986:

See also

 Npower (UK)

 Timeline of the UK electricity supply industry
 List of power stations in Wales
 Hydroelectricity in the United Kingdom
 Dolgarrog power station

References

External links

Hydroelectric power stations in Wales
Grade II* listed buildings in Gwynedd
Beddgelert
Energy infrastructure completed in 1905
1905 establishments in Wales
Podlaska Wytwórnia Samolotów. Podlaska Wytwórnia Samolotów (PWS; Podlachian Aircraft Factory) was a Polish aerospace manufacturer between 1923 and 1939, located in Biała Podlaska.

History
Podlaska Wytwórnia Samolotów SA was created in 1923. The first aircraft produced were 35 Potez XV bombers for the Polish Air Force, under the French licence, built from 1925. By 1929 the company had produced 150 Potez XXV and 155 Potez 27, under French licence, and 50 PWS-A fighters, which was the Czech Avia BH-33 built under licence. It also produced 50 Bartel BM-4 trainers in 1931, designed by Samolot.

In 1925, a design office was established which included, among others, Stefan Cywiński, Zbysław Ciołkosz, August Bobek-Zdaniewski. Despite a large number of prototypes, few were produced in series. The first aircraft of their own design to be mass-produced was the PWS-10 fighter of 1930 of which 80 examples were built. Smaller production runs of the PWS-14 trainer  and the PWS-24 passenger aircraft were also made. The PWS-10 and PWS-24 were the first fighter and the first passenger plane of the Polish construction built in series, respectively. In 1929 the factory built a wind tunnel, the first in Poland. All PWS-designed aircraft had wooden or mixed construction.

In 1932 the PWS was nationalized to prevent its bankruptcy. It then produced 500 RWD-8 trainers  (designed by RWD) and 50 of the British Avro Tutor under licence as the PWS-18 trainers. The factory then designed its own successful PWS-16 and PWS-26 advanced trainers, 320  of the latter built from 1936 to 1939.

In 1936 the factory was subordinated to the Państwowe Zakłady Lotnicze (PZL). It developed a series of projects for military planes, but they were not built due to outbreak of World War II. The PWS-33 Wyżeł twin-engine advanced trainer and the PWS-35 sports biplane were ordered into production but no aircraft were delivered before the outbreak of war.

Lwowskie Warsztaty Lotnicze (LWL, Lwów Aviation Workshops) was formed in October 1937 as a division of PWS. It built gliders, among others designated with letters PWS. Some 160 gliders were built before the war.

After the outbreak of World War II, the PWS factory was bombed by the Germans on September 4, 1939, who destroyed about 70% of the factory. The remains of equipment were plundered by the Soviets after their invasion of Poland.

Aircraft

References

Notes

Bibliography

 Glass, Andrzej. Polskie konstrukcje lotnicze 1893-1939 [Polish aviation designs 1893-1939]. Warsaw: WKiŁ, 1977 (no ISBN)

External links

 Podlaska Wytwórnia Samolotów – Muzeum Lotnictwa Polskiego 
 Podlaska Wytwórnia Samolotów / PWS – Samoloty w Lotnictwie Polskim 

Aircraft manufacturers of Poland
Economy of the Second Polish Republic
Science and technology in Poland
Biała Podlaska
PWS aircraft
Companies set up in the Second Republic of Poland
Telepathy (software). Telepathy is a software framework which can be used to make software for interpersonal communications such as instant messaging, Voice over IP or videoconferencing. Telepathy enables the creation of communications applications using components via the D-Bus inter-process communication mechanism. Through this it aims to simplify development of communications applications and promote code reuse within the free software and open source communities by defining a logical boundary between the applications and underlying network protocols.

Implementations
There are free software implementations of various protocols that export Telepathy interfaces:

 Gabble: for XMPP, including support for Jingle
 Butterfly: for Windows Live Messenger
 Idle: for Internet Relay Chat
 Salut: for the link-local XMPP protocol
 Haze: for accessing protocols supported by libpurple, the library used by the Pidgin messaging client. This was done as a Google Summer of Code project in 2007.
 Spirit: for the Skype protocol on the Nokia N900 and Nokia N9
 Rakia: for the Session Initiation Protocol (SIP), using Nokia's open source Sofia-SIP library
 Morse: for Telegram

Mission Control is the name of the component that provides a way for end-user applications to abstract some details of low level telepathy components such as connection managers.

Tubes are Telepathy's mechanism for supporting arbitrary data transfer and remote IPC.

Telepathy forms the basis of the instant messaging and voice/video calling software  on the Nokia 770, N800, N810, N900, N9 and Jolla.

How Telepathy works
Protocol implementations provide a D-Bus service called a connection manager. Telepathy clients use these to create connections to services. Once a connection is established, further communication happens using objects called channels which are requested from the connection. A channel might be used to send and receive text messages, or represent the contact list, or to establish a VoIP call.

Applications
 Empathy
 KDE Telepathy
 Sugar

See also

 Farstream (formerly Farsight)

References

External links
 Project website
 "IM/VOIP Communications Framework" video download (77MB ogg) of talk by lead developer Robert McQueen on Telepathy. Streaming Flash video.
 KDE-Telepathy actual 0.9.0
 Telepathy Developer's Manual

Applications using D-Bus
Free instant messaging clients
Free network-related software
Freedesktop.org
Bonding-studenteninitiative e.V.. The bonding-studenteninitiative e.V. (short name bonding) is an independent, non-political and non-profit student organisation. It was founded in 1988 in Aachen, Germany. The name derives from wire bonding, where interconnections between an integrated circuit and its outer world are made.

Its aim is to develop students of engineering and natural sciences for professional life. This aim is mainly followed by the bonding-Firmenkontaktmesse (a job fair) which is organised every year at each location. Additionally, bonding organises company visits, company presentations, case studies, softskill trainings and more. These projects are for free for the participating students.

bonding is a member of the Cologne Round Table (Kölner Runde).

bonding consists of twelve local groups which are mainly located in the technical universities of the following towns in Germany:

 Aachen
 Berlin
 Bochum
 Braunschweig
Bremen
 Dresden
 Erlangen
 Hamburg
 Kaiserslautern
 Karlsruhe
 Munich
 Stuttgart

Partner organisations 

 Canadian Federation of Engineering Students (CFES, since 2005)
 Cologne Round Table (Kölner Runde / Cologne Round Table)

References

External links 
http://www.bonding.de

1988 establishments in West Germany
Engineering education
Student organisations in Germany
Scientific organisations based in Germany
BlueBEEP. BlueBEEP was a popular blue boxing computer program for MS-DOS written between 1993–1995 by the German programmer Stefan Andreas Scheytt, known by the pseudonym Onkel Dittmeyer. Used correctly, it could be used to exploit vulnerabilities in the CCITT Signaling System No. 5, used by international telephone switches of this era, to make free calls around the world. The program spread via the bulletin board systems and was popular with phreaks, hackers and the warez community.

The Pascal source code was released to the public along with the final version on April 1, 1995.

BlueBEEP has been praised as "the most finely programmed phreaking tool ever coded".

The install docs report the build system as follows: "386-40 8meg with 530meg HDD and SB/16+SVGA, a Philips 102-key soft-keyboard, a 2001 canadian keyboard and a GENIUS 4-year-old shoplifted 3-button mouse."

References

Further reading

External links 
BlueBEEP Executable 
BlueBEEP v1.00 Pascal Source Code

DOS software
Phreaking
Diphenyl diselenide. Diphenyl diselenide is the chemical compound with the formula (C6H5)2Se2, abbreviated Ph2Se2.  This yellow-coloured solid is the oxidized derivative of benzeneselenol.  It is used as a source of the PhSe unit in organic synthesis.

Preparation and properties 
Ph2Se2 is prepared by the oxidation of benzeneselenoate, the conjugate base of benzeneselenol which is generated via the Grignard reagent:

PhMgBr + Se → PhSeMgBr
2 PhSeMgBr + Br2 → Ph2Se2 + 2 MgBr2

The molecule has idealized C2-symmetry, like hydrogen peroxide and related molecules. The Se-Se bond length of 2.29 Å the C-Se-Se-C dihedral angle is 82° and the C-Se-Se angles are near 110°.

Medical applications 
Diphenyl diselenide alleviates methylmercury poisoning in grass carp.

Reactions
A reaction characteristic of Ph2Se2 is its reduction:
Ph2Se2 + 2 Na → 2 PhSeNa

PhSeNa is a useful nucleophile used to introduce the phenylselenyl group by nucleophilic substitution of alkyl halides, alkyl sulfonates (mesylates or tosylates) and epoxides. The example below was taken from a synthesis of morphine.

Another characteristic reaction is chlorination:
Ph2Se2 + Cl2 → 2 PhSeCl

PhSeCl is a powerful electrophile, used to introduce PhSe groups by reaction with a variety of nucleophiles, including enolates, enol silyl ethers, Grignard reagents, organolithium reagents, alkenes and amines. In the sequence below (early steps in the synthesis of Strychnofoline), a PhSe group is introduced by reaction of a lactam enolate with PhSeCl. This sequence is a powerful method for the conversion of carbonyl compounds to their α,β-unsaturated analogs.

Diphenyl diselenide itself is also a source of a weakly electrophilic PhSe group in reactions with relatively powerful nucleophiles like Grignard reagents, lithium reagents and ester enolates (but not ketone enolates or weaker nucleophiles). PhSeCl is both more reactive, and more efficient, since with Ph2Se2 half of the selenium is wasted.

Ph2Se2 + Nu− → PhSeNu + PhSe−

N-Phenylselenophthalimide (N-PSP) can be used if PhSeCl is too strong and diphenyl diselenide is too weak or wasteful.

References

Organoselenium compounds
Phenyl compounds
Valmet Vihuri. Valmet Vihuri (Finnish for Gale) was a Finnish advanced two-seat fighter trainer aircraft, serving in the Finnish Air Force between 1953 and 1959. Only a few airframes have survived, including one at the Central Finland Aviation Museum in Finland.

History
In spite of their economic problems, the aircraft manufacturer Valmet began designing a new aircraft at the beginning of the 1950s, to replace the aging Finnish Air Force (FAF) VL Pyrys. Martti Vainio was the chief designer of the project. Most of the planning was made by the aeronautical engineers L. Hämäläinen and T. Mäntysalo in 1948–49. The Bristol Mercury, then being manufactured under license in Finland for the Bristol Blenheim bomber, was chosen as the engine, since it was readily available. The prototype (VH-1) made its first flight on 6 February 1951, in Tampere, piloted by captain Esko Halme. After successful test flights, the FAF ordered 30 production aircraft, called Valmet Vihuri II, on 27 February 1951. In the autumn of 1954, the Air Force ordered a further 20 aircraft of the developed version Valmet Vihuri III. All the aircraft of the third version were handed over to the Air Force on 15 January 1957.

Valmet built 51 Vihuris in three different models in Kuorevesi and Tampere. The aircraft had the registration codes VH-1 through VH-51.

Operational use

The Vihuri aircraft became the most-used aircraft in FAF service by the mid-1950s. The aircraft was subject to many accidents, and the press raised much concern over this. The safety of the Vihuri even became a matter for the government. In May 1959, the aircraft was permanently grounded. Attempts were made to sell the aircraft to Tunisia, without success.

After inspection, it became apparent that the type and its design were sound; most of the accidents were due to pilots' often grave violations of flight regulations, and the fact that all airframes were well worn by the end of the 1950s. The other problem was the engines. The engines used, Tampella Mercury, were recycled engines of wartime Bristol Blenheim bombers which were already worn out. The planes were sold for scrap to Moser OY. One airframe, VH-18, survives in the Central Finland Aviation Museum, and the fore fuselage of another, VH-25, is being restored. The canopies of the scrapped aircraft remain today as the roof windows of the Kuusakoski metal-recycling plant in Espoo.

Operators

Finnish Air Force

Surviving aircraft
The Central Finland Aviation museum is displaying the VH-18, which is the only preserved Vihuri. It gathered 802 flying hours, after which the aircraft served as an educational machine at the Air Force Academy in Kauhava.

Specifications (Valmet Vihuri II)

See also

References

Footnotes

Notes

Bibliography

 Bridgman, Leonard. Jane's All The World's Aircraft 1956–57, New York: The McGraw-Hill Book Company, 1956. 
 Kalevi Keskinen, Kari Stenman, Klaus Niska: Suomen ilmavoimien historia 14 - Suomalaiset hävittäjät, AR-Kustannus ky, 1990.

External links

 Pictures from the scrapping of the Vihuris

1950s Finnish military trainer aircraft
Valmet aircraft
Single-engined tractor aircraft
Aircraft first flown in 1951
Low-wing aircraft
Shift kit. A shift kit is a set of components for automobiles designed to improve how well the car shifts between gears. Kits are made for both automatic and manual transmissions.

Towing considerations
During a shift, power is lost in the clutch (for automatic transmissions the clutches are usually internal) due to clutch slip and the difference between the current and final output shaft speeds. This makes a quick shift more desirable when towing, to reduce clutch wear and heat developed in the transmission. Balancing this, too quick a shift increases peak mechanical loads on the transmission, engine and drive train; an instant shift would cause impact loads and lead to early mechanical failure, as well as an unpleasant driving experience.

Manual transmission kit
For manual transmission equipped cars, it is a component that replaces the stock gear selector (shifter). A shift kit usually shortens the throws of selecting a gear (also known as a short throw shift or short shifter), therefore allowing a driver to reduce the shift time and change gears more efficiently.

Automatic transmission kit
An automatic transmission's main focus is smooth shifting between gears. To accomplish this it often goes into two gears at once while shifting up, which is known as a shift overlap. In these cars, it is a kit that can reduce or eliminate the shift overlap. It will also reduce wear because the transmission won't be trying to drive in two gears at once.

History
The term "Shift Kit" is a registered trademark of the company "TransGo" which originated the development of automatic transmission valve body improvement and upgrade components such as springs, valves, and instructional materials to improve the shift characteristics and durability of automatic transmissions.

References

Automotive accessories
Automotive transmission technologies
Automotive industry
Vehicle modifications
Ferroelectret. A ferroelectret, also known as a piezoelectret, is a thin film of polymer foams, exhibiting piezoelectric and pyroelectric properties after electric charging.  Ferroelectret foams usually consist of a cellular polymer structure filled with air. Polymer-air composites are elastically soft due to their high air content as well as due to the size and shape of the polymer walls. Their elastically soft composite structure is one essential key for the working principle of ferroelectrets, besides the permanent trapping of electric charges inside the polymer voids. The elastic properties allow large deformations of the electrically charged voids. However, the composite structure can also possibly limit the stability and consequently the range of applications.

How it works

The most common effect related to ferroelectrets is the direct and inverse piezoelectricity, but in these materials, the effect occurs in a way different from the respective effect in ferroelectric polymers. In ferroelectric polymers, a stress in the 3-direction mainly decreases the distance between the molecular chains, due to the relatively weak van der Waals and electrostatic interactions between chains in comparison to the strong covalent bonds within the chain. The thickness decrease thus results in an increase of the dipole density and thus in an increase of the charges on the electrodes, yielding a negative d33 coefficient from dipole-density (or secondary) piezoelectricity. In cellular polymers (ferroelectrets), stress in the 3-direction also decreases the thickness of the sample. The thickness decrease occurs dominantly across the voids, the macroscopic dipole moments decrease, and so do the electrode charges, yielding a positive d33 (intrinsic or direct (quasi-)piezoelectricity).

New features

In recent years, alternatives to the cellular-foam ferroelectrets were developed. In the new polymer systems, the required cavities are formed by means of e.g. stamps, templates, laser cutting, etc. Thermo-forming of layer systems from electret films led to thermally more stable ferroelectrets.

Notes

References
 
 
 
 

Condensed matter physics
Electrical phenomena
IBM Balanced Configuration Unit. The IBM Data Warehousing Balanced Configuration Unit is a family of data warehousing servers from IBM. IBM introduced the Balanced Configuration Unit (BCU) for AIX in 2005, and the BCU for Linux in 2006.  The BCU is a "balanced" combination of computer server hardware (cpus, I/O channels, and storage) combined with DB2 Data Warehouse Edition (DB2 DWE) software to form a data warehouse "appliance like" system to compete with systems such as Greenplum, DATAllegro, Netezza Performance Server, and Teradata. 

See also IBM Linux Solution Optimizes Enterprise Data Warehousing.

External links
 IBM's InfoSphere Balanced Warehouse web page: 

Balanced
Léon-Mba International Airport. Léon-Mba International Airport  is an airport situated in Libreville, Gabon. Constructed in the 1950s, it is the main international airport in the country.

Airlines and destinations

Passenger

Cargo

Accidents and incidents
 On 2 April 1977, an Aviogenex (Yugoslavia) Tupolev Tu-134 registered YU-AJS, crashed on landing, killing the eight crew on board.
 On 8 June 2004, a Gabon Express twin-engine Hawker Siddeley HS 748 operating Gabon Express Flight 221 ditched into the Gulf of Guinea after suffering an engine failure and hydraulic problems shortly after take-off, leading to the deaths of 19 out of the 30 onboard.
 On 6 June 2011, Antonov An-26 TR-LII of Solenta Aviation, operating Flight 122A for DHL Aviation ditched in the sea near Libreville International Airport. Four people on board were rescued and transported to a local hospital, but were not seriously injured. The crew reported hydraulic problems and eyewitnesses stated that the aircraft's propellers were not turning at the time of the ditching.

See also
 List of airports in Gabon
 Transport in Gabon

References

External links
Libreville International Airport official website

Airports in Gabon
Buildings and structures in Libreville
Military installations of France in other countries
Denel Land Systems. Denel Land Systems is a division of the Denel group.

It was formerly Lyttelton Engineering Works (LIW—from ), a subsidiary part of the commercial network from Armscor. It then became the Systems division of the Land Systems Group of Denel.

They are responsible for the design and manufacture of systems ranging from artillery (such as G5 howitzer and G6 howitzer) to small arms such as the R4 assault rifle.

Products

Vehicles
 Rooikat: 8×8 armoured combat vehicle with a GT4  gun in turret
 Badger IFV:  8×8 wheeled infantry fighting vehicle
 G7: T7-52  light howitzer
 G5: T6-52  towed howitzer
 G6 Rhino: T6-52  self-propelled howitzer 
 G6 Marksman: G6 base vehicle combined with a British Marksman SPAAG turret

Turrets
 MCT 12.7: Turret with  machine gun
 LCT 20: Turret with a GA-1  gun
 LCT 30: Turret with a GI-30  gun
 MCT 30: Turret with a GI-30  gun
 LCT 30 ATGM: Turret with a GI-30  gun and four Ingwe ATGM launchers
 LMT 105: Turret with a GT7  tank gun 
 T7-52: Turret with a GT7  howitzer gun
 T6-52: Turret with a Denel 155mm Howitzer Gun  howitzer gun
 T5-52: Turret with a Denel 155mm Howitzer Gun  truck-mounted howitzer gun
 MCT 60 Mortar: Turret with a M10 Mortar  mortar
 MCT Missile: Turret with two Ingwe ATGM launchers
 Vektor GA-1:  gun for turrets 
 Denel GI-2  gun for turrets or naval applications
 Denel GI 30:  gun for turrets
 Denel 35mm Dual Purpose Gun:  naval gun close-in weapons system
 Denel GT4:  rifled gun for turrets
 Denel GT7:  light gun for turrets
 Denel 155mm Howitzer Gun:  heavy gun for turrets

Mortar systems
 M10 Mortar:  mortar for turrets
 M4 60:  commando mortar 
 M6 60:  mortar
 M8 81:  mortar

Small arms
 Vektor SP1:  semi-automatic pistol
 Vektor R1/R2/R3:  battle rifle
 Vektor R4/R5/R6:  assault rifle
 Vektor CR-21:  bullpup assault rifle (prototype only)
 Vektor Mini-SS:  light machine gun
 Vektor Mini-SS Compact:  compact light machine gun
 Vektor SS-77:  medium machine gun
 Vektor DMG-5:  medium machine gun
 Denel NTW-20: , , &  anti-materiel rifle
 Denel Y3 AGL:  automatic grenade launcher

References

External links
 

Denel
Firearm manufacturers of South Africa
Military vehicle manufacturers
Weapons manufacturing companies