vania-janet/multiturn-rag-retrieval-data huggingface dataset:
British Army during World War I
Once the infantry had reached the German trenches , the artillery shifted from the creeping barrage to the standing barrage , a static barrage that would protect the infantry from counter-attack while they consolidated the position . A variant was the box barrage , in which three or four barrages formed a box -- or more often three sides of a box -- around a position to isolate and prevent reinforcements being brought up into the front line . This was normally used to protect trench raids , although it could also be used offensively against a German unit . Another type of barrage was the SOS barrage , fired in response to a German counterattack . An SOS barrage could be brought down by firing a flare signal of a pre arranged colour , as a German barrage tended to cut the telephone lines . A pre-registered barrage would then descend on No Man 's Land .
Rainwater harvesting
Rainwater harvesting is one of the simplest and oldest methods of self - supply of water for households usually financed by the user .
Switch
In either case , the standard method for minimizing arc formation and preventing contact damage is to use a fast - moving switch mechanism , typically using a spring - operated tipping - point mechanism to assure quick motion of switch contacts , regardless of the speed at which the switch control is operated by the user . Movement of the switch control lever applies tension to a spring until a tipping point is reached , and the contacts suddenly snap open or closed as the spring tension is released .
Van de Graaff generator
In the example , the lower roller ( 6 ) is metal , which picks negative charge off the inner surface of the belt . The lower comb ( 7 ) develops a high electric field at its points that also becomes large enough to ionize air molecules . In this case the electrons are attracted to the comb and positive air ions neutralize negative charge on the outer surface of the belt , or become attached to the belt . The exact balance of charges on the up - going versus down - going sides of the belt will depend on the combination of the materials used . In the example , the upward - moving belt must be more positive than the downward - moving belt . As the belt continues to move , a constant `` charging current '' travels via the belt , and the sphere continues to accumulate positive charge until the rate that charge is being lost ( through leakage and corona discharges ) equals the charging current . The larger the sphere and the farther it is from ground , the higher will be its peak potential . In the example , the wand with metal sphere ( 8 ) is connected to ground , as is the lower comb ( 7 ) ; electrons are drawn up from ground due to the attraction by the positive sphere , and when the electric field is great enough ( see below ) the air breaks in the form of an electrical discharge spark ( 9 ) . Since the material of the belt and rollers can be selected , the accumulated charge on the hollow metal sphere can either be made positive ( electron deficient ) or negative ( excess electrons ) .
Sapper
A sapper , in the sense first used by the French military , was one who dug trenches to allow besieging forces to advance towards the enemy defensive works and forts , over ground that is under the defenders ' musket or artillery fire . This digging was referred to as sapping the enemy fortifications . Saps were excavated by brigades of trained sappers or instructed troops . When an army was defending a fortress with cannons , they had an obvious height and therefore range advantage over the attacker 's guns . The attacking army 's artillery had to be brought forward , under fire , so as to facilitate effective counter-battery fire .
Pelton wheel
The conduit bringing high - pressure water to the impulse wheel is called the penstock . Originally the penstock was the name of the valve , but the term has been extended to include all of the fluid supply hydraulics . Penstock is now used as a general term for a water passage and control that is under pressure , whether it supplies an impulse turbine or not .
Switch
In electrical engineering , a switch is an electrical component that can `` make '' or `` break '' an electrical circuit , interrupting the current or diverting it from one conductor to another . The mechanism of a switch removes or restores the conducting path in a circuit when it is operated . It may be operated manually , for example , a light switch or a keyboard button , may be operated by a moving object such as a door , or may be operated by some sensing element for pressure , temperature or flow . A switch will have one or more sets of contacts , which may operate simultaneously , sequentially , or alternately . Switches in high - powered circuits must operate rapidly to prevent destructive arcing , and may include special features to assist in rapidly interrupting a heavy current . Multiple forms of actuators are used for operation by hand or to sense position , level , temperature or flow . Special types are used , for example , for control of machinery , to reverse electric motors , or to sense liquid level . Many specialized forms exist . A common use is control of lighting , where multiple switches may be wired into one circuit to allow convenient control of light fixtures .
Climate of India
Cyclone 05B , a supercyclone that struck Orissa on 29 October 1999 , was the deadliest in more than a quarter - century . With peak winds of 160 miles per hour ( 257 km / h ) , it was the equivalent of a Category 5 hurricane . Almost two million people were left homeless ; another 20 million people lives were disrupted by the cyclone . Officially , 9,803 people died from the storm ; unofficial estimates place the death toll at over 10,000 .
Telephone exchange
Circuits interconnecting switches are called trunks . Before Signalling System 7 , Bell System electromechanical switches in the United States communicated with one another over trunks using a variety of DC voltages and signaling tones . It would be rare to see any of these in use today .
Great Pacific garbage patch
Dutch innovator Boyan Slat has been working on an ocean cleanup array that is a passive system that will float on the ocean surface and collect plastic in the Great Pacific garbage patch Based on his 2012 TedEx talk . However , he recently announced there is a new prototype that is more efficient , cost effective and will theoretically collect plastic faster . The new prototype is scheduled to be in service in 12 months , roughly in 2019 , and is a simplified version of the first prototype designed . This new prototype will be smaller and have floating anchors approximately 600 meters beneath the surface , floating with the currents to where the plastic trash is located .
Switch
The terms pole and throw are also used to describe switch contact variations . The number of `` poles '' is the number of electrically separate switches which are controlled by a single physical actuator . For example , a `` 2 - pole '' switch has two separate , parallel sets of contacts that open and close in unison via the same mechanism . The number of `` throws '' is the number of separate wiring path choices other than `` open '' that the switch can adopt for each pole . A single - throw switch has one pair of contacts that can either be closed or open . A double - throw switch has a contact that can be connected to either of two other contacts , a triple - throw has a contact which can be connected to one of three other contacts , etc .
Hot air balloon
The most common type of top vent is a disk - shaped flap of fabric called a parachute vent , invented by Tracy Barnes . The fabric is connected around its edge to a set of `` vent lines '' that converge in the center . ( The arrangement of fabric and lines roughly resembles a parachute -- thus the name . ) These `` vent lines '' are themselves connected to a control line that runs to the basket . A parachute vent is opened by pulling on the control line . Once the control line is released , the pressure of the remaining hot air pushes the vent fabric back into place . A parachute vent can be opened briefly while in flight to initiate a rapid descent . ( Slower descents are initiated by allowing the air in the balloon to cool naturally . ) The vent is pulled open completely to collapse the balloon after landing .
Tropical cyclone
There are two sources of heat input . The dominant source is the input of heat at the surface , primarily due to evaporation . The bulk aerodynamic formula for the rate of heat input per unit area at the surface , Q i n : k ( \ displaystyle Q_ ( in : k ) ) , is given by
Tap and die
Twin chucking : tap is held at points of both its circular and square cross-section . Gripping the circular section assures concentricity to the machine spindle , and gripping the square produces positive rotational drive . Safety clutch : The built in safety mechanism operates as soon as the set torque limit is attained to save the tap from breakage . Float radial parallel : small misalignments are taken care of by this float . Length compensation : built in length compensation takes care of small push or pull to the spindle or feed difference .
Parameter (computer programming)
A common use case in C and related languages is for exception handling , where a function places the return value in an output variable , and returns a boolean corresponding to whether the function succeeded or not . An archetypal example is the TryParse method in . NET , especially C# , which parses a string into an integer , returning true on success and false on failure . This has the following signature : public
Grip (job)
Grips also set `` passive fill '' which is a term for the reflected light that is `` bounced '' back onto a subject on the fill or non-key light side . The first choice for most film - makers ' fill is a product known in the US as beadboard and called `` poly '' , short for polystyrene , in Europe . It is rigid insulation made for the construction trade , but was adopted by the film trade because of its `` true - white '' color and `` soft '' bounce .
Recursion (computer science)
A wrapper function is a function that is directly called but does not recurse itself , instead calling a separate auxiliary function which actually does the recursion .
River Welland
The people of Market Deeping , Deeping Gate and Deeping St James , together with other villages along the river presented a petition to Elizabeth I , requesting that the fens should be drained , as the banks of the river and of the neighbouring Glen were in a poor state of repair . They suggested that Thomas Lovell should undertake the work , which he did , at a cost of £ 12,000 , for which he received 15,000 acres ( 6,100 ha ) of the land which was reclaimed as a result of the work . Unrest in the early 1600s resulted in most of the works being destroyed , but in 1632 a group of adventurers led by the Earl of Bedford were granted permission to drain Deeping Fen , South Fen and Crowland . The work included making the Welland deeper and wider from Deeping St James to its outfall beyond Spalding , and the construction of side drains . These included a drain running from Pode Hole to below Spalding , which is still known as Vernatt 's Drain , after one of the adventurers called Sir Philibert Vernatti . Although declared completed in 1637 , efficient drainage would have to wait until the construction of Pode Hole pumping station in 1827 .
High-voltage direct current
A back - to - back station ( or B2B for short ) is a plant in which both converters are in the same area , usually in the same building . The length of the direct current line is kept as short as possible . HVDC back - to - back stations are used for
River Welland
Several prominent civil engineer considered the problems of Deeping Fen and the river outfall at the end of the 1700s . Two reports were produced , one by George Maxwell , and the second by Edward Hare , who had been assisted by William Jessop and John Rennie . They formed the basis for the Deeping Fen Act of 1801 . The channel above Spalding was made deeper , the north bank was made stronger , and the North and South Drove Drains were enlarged through the fen . One of Rennie 's recommendations had been to replace the windmills which drove the drainage pumps with a steam pumping station at Pode Hole , but this was not implemented . After reports by Rennie and Thomas Pear in 1815 , and by Rennie alone in 1818 and 1820 , the provision of steam engines was authorised by an act in 1823 . The trustees appointed by the 1801 act continued to manage Deeping Fen until they were replaced in 1939 by the Deeping Fen , Spalding and Pinchbeck Internal Drainage Board , subsequently renamed the Welland & Deepings Internal Drainage Board .
River Welland
( hide ) River Welland Legend The Wash Holbeach River A17 Fosdyke bridge Five Towns Drain + Pumping Station Risegate Eau River Glen Vernatt 's Drain Vernatt 's Bridge Sluice River Welland A16 bridge Coronation Channel Fulney Lock , Marsh Road sluice A151 Holbeach Road bridge Spalding Cowbit Road sluice New River A16 bridges Cowbit wash Crowland Fodder Lots B1166 Crowland Former channel to South Ea Crowland High Wash Folly River ( limit of navigation ) Old course and Maxey Cut Railway bridges Deeping Low Lock B1162 Deeping Gate bridge Briggin 's ( Deeping High ) Lock B1524 Market Deeping bridge Stamford Canal Market Deeping mill A15 bridges Greatford Cut ( from River Glen ) Molecey 's and Maxey mills King Street ( Roman road ) West Deeping and Lolham mills Lolham railway bridge Tallington Mill Old course weir weir 5 locks River Gwash Hudd 's Mill and ford Stamford Canal Weir Stamford wharf A16 St Martin 's Bridge Pumping Station to Rutland Water A1 Road bridge River Chater Melton - Peterborough Railway bridge A47 road bridge , Duddington Welland Viaduct ( Melton - Corby Rly ) To Source
Corrosion
In any given environment ( one standard medium is aerated , room - temperature seawater ) , one metal will be either more noble or more active than others , based on how strongly its ions are bound to the surface . Two metals in electrical contact share the same electrons , so that the `` tug - of - war '' at each surface is analogous to competition for free electrons between the two materials . Using the electrolyte as a host for the flow of ions in the same direction , the noble metal will take electrons from the active one . The resulting in mass flow or electric current can be measured to establish a hierarchy of materials in the medium of interest . This hierarchy is called a galvanic series and is useful in predicting and understanding corrosion .
Irrigation tank
An irrigation tank or tank is an artificial reservoir of any size . They are mainly found in India . ( The word sagar refers to a large lake , usually man - made ) . It can also have a natural or man - made spring included as part of a structure . Tanks are part of an ancient tradition of harvesting and preserving the local rainfall and water from streams and rivers for later use , primarily for agriculture and drinking water , but also for sacred bathing and ritual . Often a tank was constructed across a slope so to collect and store water by taking advantage of local mounds and depressions . Tank use is especially critical in parts of South India without perennial rainfall where water supply replenishment is dependent on a cycle of dry seasons alternating with monsoon seasons .
MAP sensor
MAP sensors measure absolute pressure . Boost sensors or gauges measure the amount of pressure above a set absolute pressure . That set absolute pressure is usually 100 kPa . This is commonly referred to as gauge pressure . Boost pressure is relative to absolute pressure - as one increases or decreases , so does the other . It is a one - to - one relationship with an offset of - 100 kPa for boost pressure . Thus a MaP sensor will always read 100 kPa more than a boost sensor measuring the same conditions . A MaP sensor will never display a negative reading because it is measuring absolute pressure , where zero is the total absence of pressure . Vacuum is measured as a negative pressure relative to normal atmospheric pressure . Vacuum - Boost sensors can display negative readings , indicating vacuum or suction ( a condition of lower pressure than the surrounding atmosphere ) . In forced induction engines ( supercharged or turbocharged ) , a negative boost reading indicates that the engine is drawing air faster than it is being supplied , creating suction . The suction is caused by throttling in spark ignition engines and is not present in diesel engines . This is often called vacuum pressure when referring to internal combustion engines .
Tropical cyclone
Size plays an important role in modulating damage caused by a storm . All else equal , a larger storm will impact a larger area for a longer period of time . Additionally , a larger near - surface wind field can generate higher storm surge due to the combination of longer wind fetch , longer duration , and enhanced wave setup .
Mississippi River
Before the Great Mississippi Flood of 1927 , the Corps 's primary strategy was to close off as many side channels as possible to increase the flow in the main river . It was thought that the river 's velocity would scour off bottom sediments , deepening the river and decreasing the possibility of flooding . The 1927 flood proved this to be so wrong that communities threatened by the flood began to create their own levee breaks to relieve the force of the rising river .
Wetland
Flood control Groundwater replenishment Shoreline stabilisation and storm protection Water purification Reservoirs of biodiversity Wetland products Cultural values Recreation and tourism Climate change mitigation and adaptation
Channel Tunnel
Precast segmental linings in the main TBM drives were used , but two different solutions were used . On the French side , neoprene and grout sealed bolted linings made of cast iron or high - strength reinforced concrete were used ; on the English side , the main requirement was for speed so bolting of cast - iron lining segments was only carried out in areas of poor geology . In the UK rail tunnels , eight lining segments plus a key segment were used ; in the French side , five segments plus a key . On the French side , a 55 - metre ( 180 ft ) diameter 75 - metre ( 246 ft ) deep grout - curtained shaft at Sangatte was used for access . On the English side , a marshalling area was 140 metres ( 459 ft ) below the top of Shakespeare Cliff , the New Austrian Tunnelling method ( NATM ) was first applied in the chalk marl here . On the English side , the land tunnels were driven from Shakespeare Cliff -- same place as the marine tunnels -- not from Folkestone . The platform at the base of the cliff was not large enough for all of the drives and , despite environmental objections , tunnel spoil was placed behind a reinforced concrete seawall , on condition of placing the chalk in an enclosed lagoon , to avoid wide dispersal of chalk fines . Owing to limited space , the precast lining factory was on the Isle of Grain in the Thames estuary , which used Scottish granite aggregate delivered by ship from the Foster Yeoman coastal super quarry at Glensanda in Loch Linnhe on the west coast of Scotland .
High-voltage direct current
Undersea cables transmission schemes ( e.g. , the 580 km NorNed cable between Norway and the Netherlands , Italy 's 420 km SAPEI cable between Sardinia and the mainland , the 290 km Basslink between the Australian mainland and Tasmania , and the 250 km Baltic Cable between Sweden and Germany ) . Endpoint - to - endpoint long - haul bulk power transmission without intermediate ' taps , ' usually to connect a remote generating plant to the main grid , for example the Nelson River DC Transmission System in Canada . Increasing the capacity of an existing power grid in situations where additional wires are difficult or expensive to install . Power transmission and stabilization between unsynchronized AC networks , with the extreme example being an ability to transfer power between countries that use AC at different frequencies . Since such transfer can occur in either direction , it increases the stability of both networks by allowing them to draw on each other in emergencies and failures . Stabilizing a predominantly AC power grid , without increasing fault levels ( prospective short - circuit current ) . Integration of renewable resources such as wind into the main transmission grid . HVDC overhead lines for onshore wind integration projects and HVDC cables for offshore projects have been proposed in North America and Europe for both technical and economic reasons . DC grids with multiple voltage - source converters ( VSCs ) are one of the technical solutions for pooling offshore wind energy and transmitting it to load centers located far away onshore . Cable
River Thames
The river is lined with various pieces of sculpture , but John Kaufman 's sculpture The Diver : Regeneration is sited in the Thames near Rainham .
Flint water crisis
Failed infrastructure and economic decline resulted in the toxic levels of lead in the city 's water supply . According to an article published in the American Journal of Public Health , to prevent another contamination crisis , officials such as Governor Snyder should consult `` professionals '' and make `` qualified '' decisions . `` Snyder and his administration introduced a corrosive water source into an aging water filtration system without adequate corrosion control ( APHA ) . '' `` I wonder how many of the individuals who made those bad decisions were professional engineers , licensed plumbers , or water - treatment specialists ? '' asked Larry Clark , Sustainable Performance Solutions LLC . In addition to professional consultation , EPA reform of water - testing techniques that concentrate on neighborhoods with lead pipes could `` ensure that all cities get an early warning when lead levels rise to the danger point . '' , said Jeff Ruch , executive director of Public Employees for Environmental Responsibility ( PEER ) . Addressing the government 's neglect in Flint 's crisis from infrastructure failure due to the city 's economic decline could prevent another municipal disaster .
Seine
Periodically the sewerage systems of Paris experience a failure known as sanitary sewer overflow , often in periods of high rainfall . Under these conditions untreated sewage is discharged into the Seine . The resulting oxygen deficit is principally caused by allochthonous bacteria larger than one micrometre in size . The specific activity of these sewage bacteria is typically three to four times greater than that of the autochthonous ( background ) bacterial population . Heavy metal concentrations in the Seine are relatively high . The pH level of the Seine at Pont Neuf has been measured to be 8.46 . Despite this , the water quality has improved significantly over what several historians at various times in the past called an `` open sewer '' .
Anticyclone
Heating of the earth near the equator forces upward motion and convection along the monsoon trough or intertropical convergence zone . The divergence over the near - equatorial trough leads to air rising and moving away from the equator aloft . As air moves towards the mid-latitudes , it cools and sinks leading to subsidence near the 30 ° parallel of both hemispheres . This circulation known as the Hadley cell forms the subtropical ridge . Many of the world 's deserts are caused by these climatological high - pressure areas . Because these anticyclones strengthen with height , they are known as warm core ridges .
Telephone exchange
Later stepping switches were arranged in banks , the first stage of which was a linefinder . If one of up to a hundred subscriber lines had the receiver lifted `` off hook '' , a linefinder connected the subscriber 's line to a free first selector , which returned the subscriber a dial tone to show that it was ready to receive dialed digits . The subscriber 's dial pulsed at about 10 pulses per second , although the speed depended on the standard of the particular telephone administration .