vania-janet/multiturn-rag-retrieval-data huggingface dataset:
High-voltage direct current
Electrochemical corrosion of long buried metal objects such as pipelines Underwater earth - return electrodes in seawater may produce chlorine or otherwise affect water chemistry . An unbalanced current path may result in a net magnetic field , which can affect magnetic navigational compasses for ships passing over an underwater cable .
River Welland
Perry was succeeded by John Grundy , Sr. , who published a paper in 1734 on flow in open drains . He calculated theoretic flow rates , and then used observation in the field to modify the results . He oversaw a programme of repairs to the Deeping Bank , which ran for 12 miles ( 19 km ) along the north and west side of the river , while John Scribo was employed to do the same for the Country Bank , which ran for 6 miles ( 9.7 km ) on the south and east . Grundy made the river deeper above Spalding , and also constructed a sluice and reservoir at the mouth of the Glen . The reservoir covered 8 acres ( 3.2 ha ) and provided water to scour the channel below the sluice . His son , John Grundy , Jr. , took over after the death of his father in 1748 , and spent nearly £ 10,000 on bank repairs between then and 1764 . He rebuilt Perry 's sluice soon after 1750 , with taller doors and a set of tide gates to prevent the tide moving upstream , and rebuilt the navigation lock in 1754 . After 1764 , Thomas Hogard became the surveyor of works , but Grundy continued to act as a consultant engineer .
Rainwater harvesting
Conceptually , a water supply system should match the quality of water with the end use . However , in most of the developed world , high - quality potable water is used for all end uses . This approach wastes money and energy and imposes unnecessary impacts to the environment . Supplying rainwater that has gone through preliminary filtration measures for nonpotable water uses , such as toilet flushing , irrigation and laundry , may be a significant part of a sustainable water management strategy .
Recursion (computer science)
Short - circuiting the base case , also known as arm 's - length recursion , consists of checking the base case before making a recursive call -- i.e. , checking if the next call will be the base case , instead of calling and then checking for the base case . Short - circuiting is particularly done for efficiency reasons , to avoid the overhead of a function call that immediately returns . Note that since the base case has already been checked for ( immediately before the recursive step ) , it does not need to be checked for separately , but one does need to use a wrapper function for the case when the overall recursion starts with the base case itself . For example , in the factorial function , properly the base case is 0 ! = 1 , while immediately returning 1 for 1 ! is a short - circuit , and may miss 0 ; this can be mitigated by a wrapper function .
Phone connector (audio)
A two - conductor TS phone connector . The connection to the sleeve is the rectangle towards the right , and the connection to the tip is the line with the notch . Wiring connections are illustrated as white circles . A three - conductor TRS phone connector . The upper connector is the tip , as it is farther away from the sleeve . The sleeve is shown connected directly to the chassis , a very common configuration . This is the typical configuration for a balanced connection . Some jacks have metal mounting connections ( which would make this connection ) and some have plastic , to isolate the sleeve from the chassis , and provide a separate sleeve connection point , as in A . This three - conductor jack has two isolated SPDT switches . They are activated by a plug going into the jack , which disconnects one throw and connects the other . The white arrowheads indicate a mechanical connection , while the black arrowheads indicate an electrical connection . This would be useful for a device that turns on when a plug is inserted , and off otherwise , with the power routed through the switches . This three - conductor jack has two normally closed switches connected to the contacts themselves . This would be useful for a patch point , for instance , or for allowing another signal to feed the line until a plug is inserted . The switches open when a plug is inserted . A common use for this style of connector is a stereo headphone jack that shuts off the default output ( speakers ) when the connector is plugged in .
Tropical cyclone
On occasion , tropical cyclones may undergo a process known as rapid deepening , a period in which the minimum sea - level pressure of a tropical cyclone decreases by 42mb in a 24 - hour period . In order for rapid deepening to occur , several conditions must be in place . Water temperatures must be extremely high ( near or above 30 ° C , 86 ° F ) , and water of this temperature must be sufficiently deep such that waves do not upwell cooler waters to the surface . Wind shear must be low ; when wind shear is high , the convection and circulation in the cyclone will be disrupted . Usually , an anticyclone in the upper layers of the troposphere above the storm must be present as well -- for extremely low surface pressures to develop , air must be rising very rapidly in the eyewall of the storm , and an upper - level anticyclone helps channel this air away from the cyclone efficiently .
Flint water crisis
The President 's action authorizes the Department of Homeland Security , Federal Emergency Management Agency ( FEMA ) , to coordinate all disaster relief efforts which have the purpose of alleviating the hardship and suffering caused by the emergency on the local population , and to provide appropriate assistance for required emergency measures , authorized under Title V of the Stafford Act , to save lives and to protect property and public health and safety , and to lessen or avert the threat of a catastrophe in Genesee County . FEMA is authorized to provide equipment and resources to alleviate the impacts of the emergency . Emergency protective measures , limited to direct federal assistance , will be provided at 75 percent federal funding . This emergency assistance is to provide water , water filters , water filter cartridges , water test kits , and other necessary related items for a period of no more than 90 days .
Anticyclone
In the absence of rotation , the wind tends to blow from areas of high pressure to areas of low pressure . The stronger the pressure difference ( pressure gradient ) between a high - pressure system and a low - pressure system , the stronger the wind . The coriolis force caused by Earth 's rotation gives winds within high - pressure systems their clockwise circulation in the northern hemisphere ( as the wind moves outward and is deflected right from the center of high pressure ) and anticlockwise circulation in the southern hemisphere ( as the wind moves outward and is deflected left from the center of high pressure ) . Friction with land slows down the wind flowing out of high - pressure systems and causes wind to flow more outward ( more ageostrophically ) from the center .
Switch
A footswitch is a rugged switch which is operated by foot pressure . An example of use is in the control of a machine tool , allowing the operator to have both hands free to manipulate the workpiece . The foot control of an electric guitar is also a footswitch .
High-voltage direct current
Under normal load , negligible earth - current flows , as in the case of monopolar transmission with a metallic earth - return . This reduces earth return loss and environmental effects . When a fault develops in a line , with earth return electrodes installed at each end of the line , approximately half the rated power can continue to flow using the earth as a return path , operating in monopolar mode . Since for a given total power rating each conductor of a bipolar line carries only half the current of monopolar lines , the cost of the second conductor is reduced compared to a monopolar line of the same rating . In very adverse terrain , the second conductor may be carried on an independent set of transmission towers , so that some power may continue to be transmitted even if one line is damaged .
Bipolar junction transistor
Forward - active ( or simply active ) The base -- emitter junction is forward biased and the base -- collector junction is reverse biased . Most bipolar transistors are designed to afford the greatest common - emitter current gain , β , in forward - active mode . If this is the case , the collector -- emitter current is approximately proportional to the base current , but many times larger , for small base current variations . Reverse - active ( or inverse - active or inverted ) By reversing the biasing conditions of the forward - active region , a bipolar transistor goes into reverse - active mode . In this mode , the emitter and collector regions switch roles . Because most BJTs are designed to maximize current gain in forward - active mode , the β in inverted mode is several times smaller ( 2 -- 3 times for the ordinary germanium transistor ) . This transistor mode is seldom used , usually being considered only for failsafe conditions and some types of bipolar logic . The reverse bias breakdown voltage to the base may be an order of magnitude lower in this region . Saturation With both junctions forward - biased , a BJT is in saturation mode and facilitates high current conduction from the emitter to the collector ( or the other direction in the case of NPN , with negatively charged carriers flowing from emitter to collector ) . This mode corresponds to a logical `` on '' , or a closed switch . Cut - off In cut - off , biasing conditions opposite of saturation ( both junctions reverse biased ) are present . There is very little current , which corresponds to a logical `` off '' , or an open switch . Avalanche breakdown region The
Telephone exchange
Rural areas , as well as the smallest towns , had manual service and signaling was accomplished with magneto telephones , which had a crank for the signaling generator . To alert the operator , or another subscriber on the same line , the subscriber turned the crank to generate ringing current . The switchboard responded by interrupting the circuit , which dropped a metal tab above the subscriber 's line jack and sounded a buzzer . Dry cell batteries , normally two large N °. 6 cells in the subscriber 's telephone , provided the direct current for the transmitter . Such magneto systems were in use in the US as late as 1983 , as in the small town , Bryant Pond , Woodstock , Maine .
Rainwater harvesting
A Dutch invention called the Groasis Waterboxx is also useful for growing trees with harvested and stored dew and rainwater . Presentation
Tropical cyclone
A hurricane or typhoon ( sometimes simply referred to as a tropical cyclone , as opposed to a depression or storm ) is a system with sustained winds of at least 34 m / s ( 66 kn ; 76 mph ; 120 km / h ) . A cyclone of this intensity tends to develop an eye , an area of relative calm ( and lowest atmospheric pressure ) at the center of circulation . The eye is often visible in satellite images as a small , circular , cloud - free spot . Surrounding the eye is the eyewall , an area about 16 kilometres ( 9.9 mi ) to 80 kilometres ( 50 mi ) wide in which the strongest thunderstorms and winds circulate around the storm 's center . Maximum sustained winds in the strongest tropical cyclones have been estimated at about 95 m / s ( 185 kn ; 210 mph ; 340 km / h ) .
Spider web
A spider web , spiderweb , spider 's web , or cobweb ( from the archaic word coppe , meaning `` spider '' ) is a device created by a spider out of proteinaceous spider silk extruded from its spinnerets , generally meant to catch its prey .
River delta
A tidal freshwater delta is a sedimentary deposit formed at the boundary between an upland stream and an estuary , in the region known as the `` subestuary '' . Drowned coastal river valleys that were inundated by rising sea levels during the late Pleistocene and subsequent Holocene tend to have dendritic estuaries with many feeder tributaries . Each tributary mimics this salinity gradient from their brackish junction with the mainstem estuary up to the fresh stream feeding the head of tidal propagation . As a result , the tributaries are considered to be `` subestuaries '' . The origin and evolution of a tidal freshwater delta involves processes that are typical of all deltas as well as processes that are unique to the tidal freshwater setting . The combination of processes that create a tidal freshwater delta result in a distinct morphology and unique environmental characteristics . Many tidal freshwater deltas that exist today are directly caused by the onset of or changes in historical land use , especially deforestation , intensive agriculture , and urbanization . These ideas are well illustrated by the many tidal freshwater deltas prograding into Chesapeake Bay along the east coastline of the United States . Research has demonstrated that the accumulating sediments in this estuary derive from post-European settlement deforestation , agriculture , and urban development .
It (novel)
During a heavy rainstorm in Derry , Maine , six - year - old George `` Georgie '' Denbrough is chasing a paper boat that was gifted to him by his brother , Bill , down a gutter . The boat is washed down a storm drain and Georgie peers in , seeing a pair of glowing yellow eyes . Georgie is confronted by a man dressed in a silver clown suit who introduces himself as `` Mr. Bob Gray '' , a.k.a. `` Pennywise the Dancing Clown '' . Pennywise offers Georgie a balloon which he cautiously refuses . The clown then entices Georgie to reach into the drain to retrieve his boat and severs his arm , causing his death .
Meander
A meander has a depth pattern as well . The cross-overs are marked by riffles , or shallow beds , while at the apices are pools . In a pool direction of flow is downward , scouring the bed material . The major volume , however , flows more slowly on the inside of the bend where , due to decreased velocity , it deposits sediment .
Ford Super Duty
To the interior , several changes were made to improve functionality for end - users . Along with the addition of a driver - side glove compartment , the truck added the option of dashboard - mounted auxiliary switches ( for owners who fit equipment such as snowplows , winches , and auxiliary lights ) ; these are switches that were typically user designed . For users that tow , a new option was Ford TowCommand , a Trailer brake controller built into the dashboard , allowing it to integrate with the ABS system and engine computer from the factory .
Rainwater harvesting
The Mumbai City council is planning to make rainwater harvesting mandatory for large societies . An attempt has been made at the Department of Chemical Engineering , IISc , Bangalore to harvest rainwater using upper surface of a solar still , which was used for water distillation
Thunderstorm
A tornado is a violent , rotating column of air in contact with both the surface of the earth and a cumulonimbus cloud ( otherwise known as a thundercloud ) or , in rare cases , the base of a cumulus cloud . Tornadoes come in many sizes but are typically in the form of a visible condensation funnel , whose narrow end touches the earth and is often encircled by a cloud of debris and dust . Most tornadoes have wind speeds between 40 and 110 mph ( 64 and 177 km / h ) , are approximately 75 metres ( 246 ft ) across , and travel several kilometers ( a few miles ) before dissipating . Some attain wind speeds of more than 300 mph ( 480 km / h ) , stretch more than 1,600 metres ( 1 mi ) across , and stay on the ground for more than 100 kilometres ( dozens of miles ) .
Tropical cyclone
In the 1960s and 1970s , the United States government attempted to weaken hurricanes through Project Stormfury by seeding selected storms with silver iodide . It was thought that the seeding would cause supercooled water in the outer rainbands to freeze , causing the inner eyewall to collapse and thus reducing the winds . The winds of Hurricane Debbie -- a hurricane seeded in Project Stormfury -- dropped as much as 31 % , but Debbie regained its strength after each of two seeding forays . In an earlier episode in 1947 , disaster struck when a hurricane east of Jacksonville , Florida promptly changed its course after being seeded , and smashed into Savannah , Georgia . Because there was so much uncertainty about the behavior of these storms , the federal government would not approve seeding operations unless the hurricane had a less than 10 % chance of making landfall within 48 hours , greatly reducing the number of possible test storms . The project was dropped after it was discovered that eyewall replacement cycles occur naturally in strong hurricanes , casting doubt on the result of the earlier attempts . Today , it is known that silver iodide seeding is not likely to have an effect because the amount of supercooled water in the rainbands of a tropical cyclone is too low .
Great Lakes region
In Wisconsin , the inner lowland has an interesting feature . It is a knob of resistant quartzites , known as Baraboo Ridge , rising from the buried upland floor through the partly denuded cover of lower Palaeozoic strata . This knob or ridge can be thought of as an ancient physiographic fossil , as it is an ancient monadnock having been preserved from destructive attacks of weather by burial under sea - floor deposits . It has been recently re-exposed through the erosion of its cover .
Chinese fire drill
The term goes back to the early 1900s , and is alleged to have originated when a ship run by British officers and a Chinese crew practiced a fire drill for a fire in the engine room . The bucket brigade drew water from the starboard side , took it to the engine room , and poured it onto the ' fire ' . To prevent flooding , a separate crew hauled the accumulated water from the engine room , up to the main deck and heaved the water over the port side . The drill had previously gone according to plan until the orders became confused in translation . The bucket brigade began to draw the water from the starboard side , run over to the port side and then throw the water overboard , bypassing the engine room completely . Additionally , the term is documented to have been used in the U.S. Marine Corps during World War II , where it was often expressed in the phrase `` as screwed up as a Chinese fire drill '' . It was also commonly used by Americans during the Korean War and the Vietnam War .
Curling
The thrower 's gripper shoe ( with the non-slippery sole ) is positioned against one of the hacks ; for a right - handed curler the right foot is placed against the left hack and vice versa for a left - hander . The thrower , now in the hack , lines the body up with shoulders square to the skip 's broom at the far end for line .
Meander
Secondary flow : A force balance exists between pressure forces pointing to the inside bend of the river and centrifugal forces pointing to the outside bend of the river . In the context of meandering rivers , a boundary layer exists within the thin layer of fluid that interacts with the river bed . Inside that layer and following standard boundary - layer theory , the velocity of the fluid is effectively zero . Centrifugal force , which depends on velocity , is also therefore effectively zero . Pressure force , however , remains unaffected by the boundary layer . Therefore , within the boundary layer , pressure force dominates and fluid moves along the bottom of the river from the outside bend to the inside bend . This initiates helicoidal flow : Along the river bed , fluid roughly follows the curve of the channel but is also forced toward the inside bend ; away from the river bed , fluid also roughly follows the curve of the channel but is forced , to some extent , from the inside to the outside bend . Ultimately , the downstream velocity of the fluid is convectively transported to the outside bend , resulting in higher velocities at the outside bend . This secondary flow effect dominates over that of irrotational flow : In real meandering rivers , we observe higher downstream fluid velocities at the outside bends .
Anticyclone
On weather maps , high - pressure centers are associated with the letter H in English , within the isobar with the highest pressure value . On constant - pressure upper - level charts , anticyclones are located within the highest height line contour .
National Flood Insurance Program
The National Flood Insurance Program ( NFIP ) is a program created by the Congress of the United States in 1968 through the National Flood Insurance Act of 1968 ( P.L. 90 - 448 ) . The program enables property owners in participating communities to purchase insurance protection , administered by the government , against losses from flooding , and requires flood insurance for all loans or lines of credit that are secured by existing buildings , manufactured homes , or buildings under construction , that are located in a community that participates in the NFIP .
Phone connector (audio)
Some sound recording devices use a three - conductor phone connector as a mono microphone input , using the tip as the signal path and the ring to connect a standby switch on the microphone .
Spider
The primitive Liphistiidae , the `` trapdoor spiders '' of the family Ctenizidae and many tarantulas are ambush predators that lurk in burrows , often closed by trapdoors and often surrounded by networks of silk threads that alert these spiders to the presence of prey . Other ambush predators do without such aids , including many crab spiders , and a few species that prey on bees , which see ultraviolet , can adjust their ultraviolet reflectance to match the flowers in which they are lurking . Wolf spiders , jumping spiders , fishing spiders and some crab spiders capture prey by chasing it , and rely mainly on vision to locate prey . Portia
Switch
One form of rotary switch consists of a spindle or `` rotor '' that has a contact arm or `` spoke '' which projects from its surface like a cam . It has an array of terminals , arranged in a circle around the rotor , each of which serves as a contact for the `` spoke '' through which any one of a number of different electrical circuits can be connected to the rotor . The switch is layered to allow the use of multiple poles , each layer is equivalent to one pole . Usually such a switch has a detent mechanism so it `` clicks '' from one active position to another rather than stalls in an intermediate position . Thus a rotary switch provides greater pole and throw capabilities than simpler switches do .
Phone connector (audio)
Other uses for these contacts have been found . One is to interrupt a signal path to enable other circuitry to be inserted . This is done by using one NC contact of a stereo jack to connect the tip and ring together when no plug is inserted . The tip is then made the output , and the ring the input ( or vice versa ) , thus forming a patch point .
Safety coffin
In 1829 , Dr. Johann Gottfried Taberger designed a system using a bell which would alert the cemetery nightwatchman . The corpse would have strings attached to its hands , head and feet . A housing around the bell above ground prevented it ringing accidentally . An improvement over previous designs , the housing prevented rainwater from running down the tube and netting prevented insects from entering the coffin . If the bell rang the watchman had to insert a second tube and pump air into the coffin with a bellows to allow the occupant to survive until the casket could be dug up . Vester
Nile
Before the placement of dams on the river the yearly discharge varied by a factor of 15 at Aswan . Peak flows of over 8,212 m / s ( 290,000 cu ft / s ) occurred during late August and early September , and minimum flows of about 552 m / s ( 19,500 cu ft / s ) occurred during late April and early May .