vania-janet/multiturn-rag-retrieval-data huggingface dataset:
HMHS Britannic
In September 2003 , an expedition led by Carl Spencer dived into the wreck . This was the first expedition to dive Britannic where all the bottom divers were using closed circuit rebreathers ( CCR ) . Diver Rich Stevenson found that several watertight doors were open . It has been suggested that this was because the mine strike coincided with the change of watches . Alternatively , the explosion may have distorted the doorframes . A number of mine anchors were located off the wreck by sonar expert Bill Smith , confirming the German records of U-73 that Britannic was sunk by a single mine and the damage was compounded by open portholes and watertight doors . Spencer 's expedition was broadcast extensively across the world for many years by National Geographic and the UK 's Channel 5 .
Bipolar junction transistor
Although these regions are well defined for sufficiently large applied voltage , they overlap somewhat for small ( less than a few hundred millivolts ) biases . For example , in the typical grounded - emitter configuration of an NPN BJT used as a pulldown switch in digital logic , the `` off '' state never involves a reverse - biased junction because the base voltage never goes below ground ; nevertheless the forward bias is close enough to zero that essentially no current flows , so this end of the forward active region can be regarded as the cutoff region .
Great Pacific garbage patch
At TEDxDelft2012 , the Dutch aerospace engineering student Boyan Slat unveiled a concept for removing large amounts of marine debris from the five oceanic gyres . Calling his project The Ocean Cleanup , he proposed to use surface currents to let debris drift to specially designed arms and collection platforms . Operating costs would be relatively modest and the operation would be so efficient that it might even be profitable . The concept makes use of floating booms , that divert rather than catch the debris . This way bycatch would be avoided , although even the smallest particles would be extracted . According to Slat 's calculations , a gyre could be cleaned up in five years ' time , collecting at least 7.25 million tons of plastic across all gyres . He also advocated `` radical plastic pollution prevention methods '' to prevent gyres from reforming .
Phone connector (audio)
This problem does not occur when using the ' gauge B ' ( BPO ) phone connector ( PO 316 ) which although it is of 0.25 in ( 6.3 mm ) diameter has a smaller tip and a recessed ring so that the ground contact of the socket never touches the tip or ring of the plug . This type was designed for balanced audio use , being the original telephone ' switchboard ' connector and is still common in broadcast , telecommunications and many professional audio applications where it is vital that permanent circuits being monitored ( bridged ) are not interrupted by the insertion or removal of connectors . This same tapered shape used in the ' gauge B ' ( BPO ) plug can be seen also in aviation and military applications on various diameters of jack connector including the PJ - 068 and ' bantam ' plugs . The more common straight - sided profile used in domestic and commercial applications and discussed in most of this article is known as ' gauge A ' .
Thunderstorm
A mesoscale convective system ( MCS ) is a complex of thunderstorms that becomes organized on a scale larger than the individual thunderstorms but smaller than extratropical cyclones , and normally persists for several hours or more . A mesoscale convective system 's overall cloud and precipitation pattern may be round or linear in shape , and include weather systems such as tropical cyclones , squall lines , lake - effect snow events , polar lows , and Mesoscale Convective Complexes ( MCCs ) , and they generally form near weather fronts . Most mesoscale convective systems develop overnight and continue their lifespan through the next day . The type that forms during the warm season over land has been noted across North America , Europe , and Asia , with a maximum in activity noted during the late afternoon and evening hours .
British Army during World War I
There were three trenches in a typical front line sector ; the fire trench , the support trench and the reserve trench , all joined by communication trenches . The trenches varied in depth , but they were usually about four or five feet deep , or in areas with a high water table a wall of sandbags would be built to allow the defenders to stand upright , fire trenches were provided with a fire step , so the occupants could return fire during an attack ( see diagram ) . Ideally , the bottom of the trench was lined with duckboards to prevent men from sinking into the mud and dugouts were cut into the walls , these gave shelter from the elements and shrapnel , although in the British Army dugouts were usually reserved for the officers and senior NCOs . The men were then expected to sleep wherever they could and in wet weather they lived under groundsheets or in tents at the bottom of the trench on the duckboards .
Spider
About half the potential prey that hit orb webs escape . A web has to perform three functions : intercepting the prey ( intersection ) , absorbing its momentum without breaking ( stopping ) , and trapping the prey by entangling it or sticking to it ( retention ) . No single design is best for all prey . For example : wider spacing of lines will increase the web 's area and hence its ability to intercept prey , but reduce its stopping power and retention ; closer spacing , larger sticky droplets and thicker lines would improve retention , but would make it easier for potential prey to see and avoid the web , at least during the day . However , there are no consistent differences between orb webs built for use during the day and those built for use at night . In fact , there is no simple relationship between orb web design features and the prey they capture , as each orb - weaving species takes a wide range of prey .
Meander
Meander formation is a result of natural factors and processes . The waveform configuration of a stream is constantly changing . Fluid flows around a bend in a vortex . Once a channel begins to follow a sinusoidal path , the amplitude and concavity of the loops increase dramatically due to the effect of helical flow sweeping dense eroded material towards the inside of the bend , and leaving the outside of the bend unprotected and therefore vulnerable to accelerated erosion , forming a positive feedback loop . In the words of Elizabeth A. Wood :
Telephone exchange
With manual service , the customer lifts the receiver off - hook and asks the operator to connect the call to a requested number . Provided that the number is in the same central office , and located on the operator 's switchboard , the operator connects the call by plugging the ringing cord into the jack on the switchboard corresponding to the called customer 's line . If the called party 's line is on a different switchboard in the same office , or in a different central office , the operator plugs into the trunk for the destination switchboard or office and asks the operator answering ( known as the `` B '' operator ) to connect the call .
Sundial
In the equatorial bow sundial , the gnomon is a bar , slot or stretched wire parallel to the celestial axis . The face is a semicircle , corresponding to the equator of the sphere , with markings on the inner surface . This pattern , built a couple of meters wide out of temperature - invariant steel invar , was used to keep the trains running on time in France before World War I .
Copper in architecture
When copper roofing , gutters , and rain leaders are electrically bonded to an earth termination facility , a pathway of low electrical impedance to ground is provided , however without dedicated conduction pathways to concentrate the discharge channel , a disperse energized surface may not be the most desirable .
Sundial
Nodus - based sundials may use a small hole or mirror to isolate a single ray of light ; the former are sometimes called aperture dials . The oldest example is perhaps the antiborean sundial ( antiboreum ) , a spherical nodus - based sundial that faces true North ; a ray of sunlight enters from the South through a small hole located at the sphere 's pole and falls on the hour and date lines inscribed within the sphere , which resemble lines of longitude and latitude , respectively , on a globe .
Elgin Marbles
To facilitate transport by Elgin , the columns ' capitals and many metopes and frieze slabs were either hacked off the main structure or sawn and sliced into smaller sections , causing irreparable damage to the Parthenon itself . One shipload of marbles on board the British brig Mentor was caught in a storm off Cape Matapan and sank near Kythera , but was salvaged at the Earl 's personal expense ; it took two years to bring them to the surface .
Phone connector (audio)
The professional audio field and the telecommunication industry use tiny telephone ( TT ) connectors in patch bays . These are mid-size TS or TRS phone plugs with a 4.40 mm ( 0.173 in ) diameter shaft and a slightly different geometry . In the telecommunications field this is termed a `` bantam '' plug . The three - conductor ( TRS for Tip - Ring - Shield ) versions are capable of handling balanced line signals and are used in professional audio installations . Though unable to handle as much power , and less reliable than a 6.35 mm ( 0.250 in ) jack , TT connectors are used for professional console and outboard patchbays in studio and live sound applications , where large numbers of patch points are needed in a limited space . The slightly different shape of bantam plugs is also less likely to cause shorting as they are plugged in .
Thunderstorm
Supercell storms are large , usually severe , quasi-steady - state storms that form in an environment where wind speed or wind direction varies with height ( `` wind shear '' ) , and they have separate downdrafts and updrafts ( i.e. , where its associated precipitation is not falling through the updraft ) with a strong , rotating updraft ( a `` mesocyclone '' ) . These storms normally have such powerful updrafts that the top of the supercell storm cloud ( or anvil ) can break through the troposphere and reach into the lower levels of the stratosphere , and supercell storms can be 24 kilometres ( 15 mi ) wide . Research has shown that at least 90 percent of supercells cause severe weather . These storms can produce destructive tornadoes , sometimes F3 or higher , extremely large hailstones ( 10 centimetres or 4 inches diameter ) , straight - line winds in excess of 130 km / h ( 81 mph ) , and flash floods . In fact , research has also shown that most tornadoes occur from this type of thunderstorm . Supercells are the strongest type of thunderstorm , even stronger than the most severe thunderstorms .
Telephone exchange
Later exchanges consisted of one to several hundred plug boards staffed by switchboard operators . Each operator sat in front of a vertical panel containing banks of 1⁄4 - inch tip - ring - sleeve ( 3 - conductor ) jacks , each of which was the local termination of a subscriber 's telephone line . In front of the jack panel lay a horizontal panel containing two rows of patch cords , each pair connected to a cord circuit .
Climate of the United Kingdom
Barometric pressure plays a role in storm systems . For the United Kingdom , record figures for barometric pressure recordings are :
Electromagnet
Some improvements can be made on the basic design . The ends of the stop and plunger are often conical . For example , the plunger may have a pointed end that fits into a matching recess in the stop . The shape makes the solenoid 's pull more uniform as a function of separation . Another improvement is to add a magnetic return path around the outside of the solenoid ( an `` iron - clad solenoid '' ) . The magnetic return path , just as the stop , has little impact until the air gap is small .
Switch
Wetting current is the minimum current needing to flow through a mechanical switch while it is operated to break through any film of oxidation that may have been deposited on the switch contacts . The film of oxidation occurs often in areas with high humidity . Providing a sufficient amount of wetting current is a crucial step in designing systems that use delicate switches with small contact pressure as sensor inputs . Failing to do this might result in switches remaining electrically `` open '' due to contact oxidation .
Water potential
Water potential integrates a variety of different potential drivers of water movement , which may operate in the same or different directions . Within complex biological systems , many potential factors may be operating simultaneously . For example , the addition of solutes lowers the potential ( negative vector ) , while an increase in pressure increases the potential ( positive vector ) . If flow is not restricted , water will move from an area of higher water potential to an area that is lower potential . A common example is water with a dissolved salt , such as sea water or the fluid in a living cell . These solutions have negative water potential , relative to the pure water reference . With no restriction on flow , water will move from the locus of greater potential ( pure water ) to the locus of lesser ( the solution ) ; flow proceeds until the difference in potential is equalized or balanced by another water potential factor , such as pressure or elevation .
Maple syrup
Improvements in tubing and vacuum pumps , new filtering techniques , `` supercharged '' preheaters , and better storage containers have since been developed . Research continues on pest control and improved woodlot management . In 2009 , researchers at the University of Vermont unveiled a new type of tap that prevents backflow of sap into the tree , reducing bacterial contamination and preventing the tree from attempting to heal the bore hole . Experiments show that it may be possible to use saplings in a plantation instead of mature trees , dramatically boosting productivity per acre .
Tap and die
Hand - tapper : A simple fixture analogous to an arbor press in its basic shape . Its spindle is thus held accurately perpendicular to the work . Standard taps are held in the spindle , and the operator turns the spindle manually via a handlebar . This fixture obviates the need for the operator to carefully and skillfully approximate perpendicularity , which even for a skilled operator can easily result in a 2 -- 5 ° error . Tapping guide , or `` tap and reamer aligner / holder '' , a simple conical guide slipped over a tap when using a regular tap handle . As with a hand - tapper , the basic principle is simply that of a jig or fixture to provide the correct alignment . Heads
Mains electricity
The line wire ( also known as phase , hot or active contact , and commonly , but technically incorrectly , as live ) , carries alternating current between the power grid and the household . The neutral wire completes the electrical circuit -- remaining at a voltage in proximity to 0 V -- by also carrying alternating current between the power grid and the household . The neutral is connected to the ground ( Earth ) , and therefore has nearly the same electrical potential as the earth . This prevents the power circuits from increasing beyond earth voltage , such as when they are struck by lightning or become otherwise charged . The earth wire or ground connects the chassis of equipment to earth ground as a protection against faults ( electric shock ) , such as if the insulation on a `` hot '' wire becomes damaged and the bare wire comes into contact with the metal chassis or case of the equipment . Further
Anticyclone
The movement of continental arctic air masses to lower latitudes produces strong but vertically shallow high - pressure systems . The surface level , sharp temperature inversion can lead to areas of persistent stratocumulus or stratus cloud , colloquially known as anticyclonic gloom . The type of weather brought about by an anticyclone depends on its origin . For example , extensions of the Azores high pressure may bring about anticyclonic gloom during the winter because they pick up moisture as they move over the warmer oceans . High pressures that build to the north and move southwards often bring clear weather because they are cooled at the base ( as opposed to warmed ) which helps prevent clouds from forming .
Blue Nile
The Blue Nile is so - called because floods during the summer monsoon erode a vast amount of fertile soil from the Ethiopian Highlands and carry it downstream as silt , turning the water dark brown or almost black .
Wetland
Prescribed Natural Regeneration There are no biophysical manipulation and the ecosystem is left to recover based on the process of succession alone . The focus of this method is to eliminate and prevent further disturbance from occurring . In order for this type of restoration to be effective and successful there must be prior research done to understand the probability that the wetland will recover with this method . Otherwise , some biophysical manipulation may be required to enhance the rate of succession to an acceptable level determined by the project managers and ecologists . This is likely to be the first method of approach for the lowest level of disturbance being that it is the least intrusive and least costly . Assisted Natural Regeneration There are some biophysical manipulations however they are non-intrusive . Example methods that are not limited to wetlands include prescribed burns to small areas , promotion of site specific soil microbiota and plant growth using nucleation planting whereby plants radiate from an initial planting site , and promotion of niche diversity or increasing the range of niches to promote use by a variety of different species . These methods can make it easier for the natural species to flourish by removing competition from their environment and can speed up the process of succession . Partial Reconstruction Here there is a mix between natural regeneration and manipulated environmental control . These manipulations may require some engineering and more invasive biophysical manipulation including ripping of subsoil , agrichemical applications such as herbicides and insecticides , laying of mulch , mechanical seed dispersal , and tree planting on a large scale . In these circumstances the wetland is impaired and without human assistance it would not recover within an acceptable period of time determine by ecologists . Again these methods of restoration will have to be considered on a site by site basis as each site will require a different approach based on levels of disturbance and ecosystem dynamics . Complete Reconstruction The most expensive and intrusive method of reconstruction requiring engineering and ground up reconstruction . Because there is a redesign of the entire ecosystem it is important that the natural trajectory of the ecosystem be considered and that the plant species will eventually return the ecosystem towards its natural trajectory .
Post box
Post boxes or mailboxes located outdoors are designed to keep mail secure and protected from weather . Some boxes have a rounded or slanted top or a down turned entry slot to protect mail from rain or snow . Locks are fitted for security , so mail can be retrieved only by official postal employees , and the box will ordinarily be constructed so as to resist damage from vandalism , forcible entry , or other causes . Bright colours are often used to increase visibility and prevent accidents and injuries . Entry openings are designed to allow the free deposit of mail , yet prevent retrieval via the access slot by unauthorised persons .
Telephone exchange
Bell System installations typically had alarm bells , gongs , or chimes to announce alarms calling attention to a failed switch element . A trouble reporting card system was connected to switch common control elements . These trouble reporting systems punctured cardboard cards with a code that logged the nature of a failure . Reed relay technology in stored program control exchange finally quieted the environment . Maintenance
Telephone exchange
The design and maintenance procedures of all systems involved methods to avoid that subscribers experienced undue changes in the quality of the service or that they noticed failures . A variety of tools referred to as make - busys were plugged into electromechanical switch elements upon failure and during repairs . A make - busy identified the part being worked on as in - use , causing the switching logic to route around it . A similar tool was called a TD tool . Delinquent subscribers had their service temporarily denied ( TDed ) . This was effected by plugging a tool into the subscriber 's office equipment on Crossbar systems or line group in step - by - step switches . The subscriber could receive calls but could not dial out .
Flint water crisis
Starting on January 7 , 2016 , Genesee County Sheriff Robert Pickell had work crews of offenders sentenced to community service begin delivering bottled water , water filters and replacement cartridges , primarily to residents living in homes built between 1901 and 1920 , whose plumbing systems are most likely leaching lead into the water . The next week , he ordered his department to begin using reverse 911 to advise homebound residents on how to get help .
Bootstrapping
A Bootstrapping Server Function ( BSF ) is an intermediary element in cellular networks which provides application independent functions for mutual authentication of user equipment and servers unknown to each other and for ' bootstrapping ' the exchange of secret session keys afterwards . The term ' bootstrapping ' is related to building a security relation with a previously unknown device first and to allow installing security elements ( keys ) in the device and the BSF afterwards .
Dismissal (cricket)
`` Caught behind '' ( an unofficial term ) indicates that a player was caught by the wicket - keeper , or less commonly by the slips . `` Caught and bowled '' ( another unofficial term ) indicates the player who bowled the ball also took the catch .
Soil erosion
Bank erosion is the wearing away of the banks of a stream or river . This is distinguished from changes on the bed of the watercourse , which is referred to as scour . Erosion and changes in the form of river banks may be measured by inserting metal rods into the bank and marking the position of the bank surface along the rods at different times .
Venus flytrap
The Venus flytrap ( also referred to as Venus 's flytrap or Venus ' flytrap ) , Dionaea muscipula , is a carnivorous plant native to subtropical wetlands on the East Coast of the United States in North Carolina and South Carolina . It catches its prey -- chiefly insects and arachnids -- with a trapping structure formed by the terminal portion of each of the plant 's leaves , which is triggered by tiny hairs on their inner surfaces . When an insect or spider crawling along the leaves contacts a hair , the trap prepares to close , snapping shut only if another contact occurs within approximately twenty seconds of the first strike . The requirement of redundant triggering in this mechanism serves as a safeguard against wasting energy by trapping objects with no nutritional value , and the plant will only begin digestion after five more stimuli to ensure it has caught a live bug worthy of consumption .