the-french-artist/wikipedia_20220301.simple_sentence_split huggingface dataset:
Birmingham Erdington
Birmingham Hall Green
Birmingham Hodge Hill
Birmingham Ladywood
Birmingham Northfield
Birmingham Perry Barr
Birmingham Selly Oak
Birmingham Sparkbrook and Small Heath
Birmingham Yardley
Coventry North East
Coventry North West
Coventry South
Dudley North
Dudley South
Halesowen and Rowley Regis
Meriden
Walsall North
Walsall South
Warley
West Bromwich East
West Bromwich West
Wolverhampton North East
Wolverhampton South East
Wolverhampton South West
Yorkshire and Humberside
Beverley and Holderness
Brigg and Goole
East Yorkshire
Great Grimsby
Haltemprice and Howden
Kingston upon Hull East
Kingston upon Hull North
Kingston upon Hull West and Hessle
City of York
Harrogate and Knaresborough
Richmond (Yorks)
Ryedale
Scarborough and Whitby
Skipton and Ripon
Barnsley Central
Barnsley East and Mexborough
Barnsley West and Penistone
Don Valley
Doncaster Central
Doncaster North
Rother Valley
Sheffield Attercliffe
Sheffield Brightside
Sheffield Central
Sheffield Hallam
Sheffield Heeley
Sheffield Hillsborough
Wentworth
Batley and Spen
Bradford North
Bradford South
Bradford West
Calder Valley
Colne Valley
Dewsbury
Hemsworth
Leeds Central
Leeds East
Leeds North East
Leeds North West
Leeds West
Morley and Rothwell
Normanton
Pontefract and Castleford
Pudsey
Shipley
Belfast East
Belfast North
Belfast South
Belfast West
East Antrim
East Londonderry
Fermanagh and South Tyrone
Foyle
Lagan Valley
Mid Ulster
Newry and Armagh
North Antrim
South Antrim
South Down
Strangford
Upper Bann
West Tyrone
Caithness, Sutherland and Easter Ross
Inverness, Nairn, Badenoch and Strathspey
Na h-Eileanan an Iar (formerly Western Isles)
Orkney and Shetland
Ross, Skye and Lochaber
North East Scotland
Aberdeen North
Aberdeen South
Banff and Buchan
Dundee East
Dundee West
West Aberdeenshire and Kincardine
Central Scotland
Ochil and South Perthshire
Perth and North Perthshire
Dunfermline and West Fife
Kirkcaldy and Cowdenbeath
North East Fife
Edinburgh East
Edinburgh North and Leith
Edinburgh South
Edinburgh South West
Edinburgh West
Linlithgow and East Falkirk
South of Scotland
Berwickshire, Roxburgh and Selkirk
Dumfriesshire, Clydesdale and Tweeddale
Ayr, Carrick and Cumnock
Central Ayrshire
Kilmarnock and Loudoun
North Ayrshire and Arran
Airdrie and Shotts
Coatbridge, Chryston and Bellshill
Cumbernauld, Kilsyth and Kirkintilloch East
East Kilbride, Strathaven and Lesmahagow
Lanark and Hamilton East
Motherwell and Wishaw
Rutherglen and Hamilton West
Glasgow Central
Glasgow East
Glasgow North
Glasgow North East
Glasgow North West
Glasgow South
Glasgow South West
Dunbartonshire
Paisley and Renfrewshire North
Paisley and Renfrewshire South
Aberavon
Alyn and Deeside
Brecon and Radnorshire
Cardiff Central
Cardiff North
Cardiff South and Penarth
Cardiff West
Carmarthen East and Dinefwr
Carmarthen West and South Pembrokeshire
Clwyd South
Clwyd West
Cynon Valley
Delyn
Islwyn
Llanelli
Meirionnydd Nant Conwy
Merthyr Tydfil and Rhymney
Neath
Newport East
Newport West
Ogmore
Preseli Pembrokeshire
Swansea East
Swansea West
Vale of Clwyd
Ynys Môn (formerly Anglesey)
List of former United Kingdom Parliamentary constituencies
Constituencies in the next United Kingdom general election - constituencies created by the four Boundary Commissions, including recommendations still pending final approval
ONS Map of Constituencies
ONS List of Constituencies (CSV file)
UK Elections Directory
TheyWorkForYou.com
A stain is a spot that has another color than the material on which it is found.
It can be occur without intention in the case of domestic stains on fabric, cloth, or other material, or it can be intentional.
Stains are used intentionally in a variety of fields, including research (biochemical staining), technology (metal staining), and art (wood staining, stained glass.)
Different types of material can be stained by different substances, and stain resistance is an important characteristic in modern textile engineering.
Various laundry techniques exist to attempt to remove or minimize existing stains, and stain removers are an important type of chemical in laundry detergents.
Some stand-alone stain removers also exist.
Substances that may create stains
fruits and their juices, particularly orange juice
ink (notably permanent marker)
sauces (particularly tomato based)
soda (particularly orange soda)
table salt
talc, cornstarch or chalk
borax
lemon juice or lemon
various fabrics in shoes
Stain removers
bleach  (do not mix with ammonia)
ammonia (do not mix with bleach)
baking soda
rubbing alcohol
hydrogen peroxide
cream of tartar
club soda
The term 'corrosion resistant steel' is used when the alloy has less than the 12% minimum of chromium, for example in the aviation industry.
There are different grades and surface finishes of stainless steel, depending on where it will be used.
Stainless steels have a higher resistance to oxidation (rust) and corrosion in many natural and man-made environments, Different stainless steels have different amounts of different metals in them, and they are good for different purposes.
There are over 150 grades of stainless steel, of which fifteen are the most used.
The idea behind stainless steel was discovered in the first part of the 19th century, but it took about 80 years to develop a reliable industrial method.
French, British and American inventors worked on this until a genuine stainless steel was produced.
The invention of modern stainless steel can be dated to 1913, and it was done by Harry Brearley in Sheffield, Yorkshire.
A common use for stainless steel is cutlery (knives, forks, and spoons).
Stainless steel cutlery was a big industry in the mid-20th century Sheffield.
Stainless steel is also used in future space rockets, like Starship and Terran R.
Articles about stainless steel  by International Stainless Steel Forum
What is stainless steel  by BSSA
Euro Inox (multilingual portal)
Comprehensive information about stainless steel by The Stainless Steel Information Center
Comprehensive information about metallurgy of stainless steel by Cambridge University
Life cycle costing of stainless steel
Introduction to stainless steel by KOSA
Ferrous is an adjective coming from the Latin ferrum (iron).
One uses this word to indicate the presence of iron, mostly in metallurgy or related industries.
"Ferrous" is also the name of a song by Peter Gabriel.
Carbon steel or plain-carbon steel, is a metal alloy.
It is a combination of two elements, iron and carbon.
Other elements are present in quantities too small to affect its properties.
The only other elements allowed in plain-carbon steel are: manganese (1.65% max), silicon (0.60% max), and copper (0.60% max).
Steel with a low carbon content has the same properties as iron, soft but easily formed.
With more carbon the metal gains hardness and strength but becomes less ductile and more difficult to weld.
Higher carbon content lowers steel's melting point and its temperature resistance in general.
Types of carbon steel
Mild (low carbon) steel: approximately 0.3% carbon content with up to 0.4% manganese content (e.g. AISI 1018 steel).
Less strong but cheap and easy to shape; surface hardness can be increased through carburizing.
Medium carbon steel: approximately 0.30% to 0.45% carbon content with 0.60 to 1.65% manganese content(e.g.
AISI 1040 steel).
Balances ductility and strength and has good wear resistance; used for large parts, forging and car parts.
High carbon steel: approximately 0.45% to 0.75%  carbon content with 0.30 to 0.90% manganese content.
Very strong, used for springs and high-strength wires.
Very high carbon steel: upto 1.5% carbon content, specially processed to produce specific atomic and molecular micro structures.
Steel can be heat-treated which allows parts to be fabricated in an easily fordable soft state.
If enough carbon is present, the alloy can be hardened to increase strength, wear, and impact resistance.
Steels are often wrought by cold-working methods, which is the shaping of metal through deformation at a low equilibrium or meta stable temperature.
Mild steel is the most common form of steel as its price is relatively low while it provides material properties that are acceptable for many applications.
Mild steel has a low carbon content (up to 0.3%) and is therefore neither extremely brittle nor ductile.
It becomes malleable when heated, and so can be forged.
It is also often used where large amounts of steel need to be formed, for example as structural steel.
Density of this metal is 7861.093 kg/m³ (0.284 lb/in³) and the tensile strength is a maximum of 500 MPa (72500 psi)
Carbon steels which can successfully undergo heat-treatment have a carbon content in the range of 0.30% to 1.70% by weight.
Trace impurities of various other elements can have a significant effect on the quality of the resulting steel.
Trace amounts of sulfur make the steel "red-short", which is a fault: the steel is brittle and crumbly.
Low alloy carbon steel, such as A36 grade, contains about 0.05% sulfur and melts around 1426–1538 °C (2600–2800 °F).
Manganese is often added to improve the hardenability of low carbon steels.
These additions turn the material into a low alloy steel by some definitions, but AISI's definition of carbon steel allows up to 1.65% manganese by weight.
Silver Steel or high-carbon bright steel, gets its name from its appearance, due to the high carbon content.
It is a very-high carbon steel, or can be thought of as some of the best high-carbon steel.
It is defined under the steel specification standards BS-1407.
It is a 1% carbon tool steel which can be ground to close tolerances.
Usually the range of carbon is minimum 1.10% but as high as 1.20%.
It also contains trace elements of 0.35% Mn (range 0.30%-0.40%), 0.40% Cr (range 0.4%-0.5%), 0.30% Si (range 0.1%-0.3%), and also sometimes sulfur (max 0.035%) and phosphorus (max 0.035%).
Silver steel is sometimes used for making straight razors, due to its ability to produce and hold a micro-fine edge.
Heat treatments
Oberg, E. et al., (
1996). "
Machinery's Handbook," 25th ed.,
Industrial Press Inc.
Smith, W.F. & Hashemi, J. (2006). "
Foundations of Materials Science and Engineering," 4th ed.,
Yellowcake is a type of uranium powder.
Yellowcake is made from rocks and minerals with uranium inside, like uraninite, after they are changed in a factory.
Yellowcake can be made into fuel for nuclear reactors, or it can be used in making atomic bombs.
Ductility is when a solid material stretches under tensile strain.
If ductile, a material may be stretched into a wire.
Malleability, a similar property, is a material's ability to deform under pressure (compressive stress).
If malleable, a material may be flattened by hammering or rolling.
Both of these properties are aspects of plasticity.
Plasticity is how far a solid material can be deformed without fracture.
These properties are commonplace in metals, and are dependent on temperature and pressure.
This was investigated by Percy Williams Bridgman as part of his 1946 Nobel Prize–winning work on high pressures.
Ductility and malleability do not always go together.
Gold has high ductility and malleability, but lead has low ductility and high malleability.
The word ductility is sometimes used to embrace both types of plasticity.
Myocardial infarction, commonly called a "heart attack"
Michigan, a United States state
Mission: Impossible - 1996 movie
Defibrillation is the act of defibrillating the heart to treat the heart when it is not pushing blood because the heart muscle is not working in any pattern.
Electricity causes a muscle to contract, this is how nerves cause muscles to work.
The heart is a large muscle, and certain parts need to contract before other parts in order to push blood through the heart and out to the rest of body correctly.
Sometimes the heart muscle doesn't contract in the correct way or at the correct speed, this is called an arrhythmia (out of rhythm).
Fibrillation is a type of arrhythmia when the whole heart is quivering, not organized to make heart beats of any kind.
CPR (Cardiopulmonary resuscitation) can get blood to the body when the heart is fibrillating, but the heart still needs to be restarted.
Sometimes CPR will do that as well, but often a defibrillator is needed.
Defibrillation is done with a defibrillator.
Defibrillation works by carefully sending a strong electric current to the heart, which resets the heart, and hopefully returns a normal, coordinated heart rhythm.
It needs to depolarise (take away the existing electric charge) from a large part of the heart muscle, which stops the arrhythmia and allows the normal heartbeat to return.
Defibrillators can work outside the body with the use of an external defibrillator or an automated external defibrillator, or inside the body with an implantable cardioverter-defibrillator.
The first use of the technique on a human was in 1947 by Claude Beck, a professor of surgery at Case Western Reserve University.
The patient was a 14-year-old boy named Mickey.
Defibrillation is now used during open heart surgery, when the heart is stopped on purpose.
In1980 the first implanted defibrillator was put into a patient.
Implanted defibrillators are put into the chests of people at risk of going into fibrillation.
Arrhythmias
Not all arrhythmias need defibrillation.
Some arrhythmias still push blood to the body, not well, but still enough to keep a person alive.
Other types, like ventricular fibrillation or pulseless ventricular tachycardia, will cause a person to die within minutes unless treated.
These are what need to be treated by defibrillation.
Fibrillation is when the heart muscle is contracting, but not in any organized way, and blood is not pumped.
Pulseless tachycardia is when the heart is beating too fast to collect any blood to push.
Asystole is when the heart is not working at all (flat-line).
Defibrillation does not work on asystole, but CPR might help.
Success rate
Defibrillation is most successful when done right when the problem starts.
Success in the first minute is about 90% and drops by 10% every minute after that.
This time can be made longer by giving the person CPR, but having a defibrillator close by is very important.
Center for Integration of Medicine and Innovative Technology
American Red Cross: Saving a Life is as Easy as A-E-D
FDA Heart Health Online: Automated External Defibrillator (AED)
Resuscitation Council (UK)
History of defibrillation
How an internal defibrillator is implanted  from Children's Hospital Heart Center, Seattle.
A defibrillator is a machine that can help when ventricular fibrillation happens in the heart of a human.
A defibrillator is a life saving device.
Fibrillation happens when many different cells in the heart begin to act as pacemaker cells.
This means that many thousands of cells tell the heart to beat, all at different times and with no rhythm.
This confusion causes the heart to become unable to move blood around the body.
This causes cardiac arrest and death.
A defibrillator sends a high energy pulse from the top-right of the heart to the bottom-middle of the heart.
This causes the whole heart to stop all activity.
The heart's normal pacemaker then can try and restart normal beating.
Defibrillation does not always work.
Types of defibrillators
Internal defibrillators
Implantable cardioverter-defibrillators (ICD) are defibrillators that are designed to help patients from inside their body.
They are put inside people that are at high-risk of going into cardiac arrest and monitor a person's heart rate, rhythm, and waveform.
By comparing the activity in the different chambers of the heart, an icd can detect cardiac arrhythmias and treat them quickly.
External defibrillators
External defibrillators are often used in hospitals and ambulances.
They are now also being used outside of medical environments more as automated external defibrillators (see below) become safer and cheaper.
There are many different types of external defibrillators, and progress in cardiac research has led to big improvements in the underlying technology.
Biphasic defibrillation
Until the 1990s, external defibrillators relied on monophasic (one phase) shock waves.
Electrical pulses are quickly sent from one electrode to the other in one direction.
Biphasic (two phases) defibrillation, however, changes the direction of the pulses.
It completes one cycle in approximately 10 milliseconds.
This means less energy is needed for successful defibrillation.
That means less risk of burns and other damage.
The small capacitor (battery) size required for the defibrillator can result in large cost and size savings.
Automated external defibrillators
An automated external defibrillator (AED) is a self-contained defibrillator device designed to be movable, and easy and simple to use.
They are often shaped like briefcases so that they can be carried by a handle.
An AED contains a battery, a control computer, and electrodes.
When the electrodes are stuck onto the patient, the control computer will assess the patient, checking the rhythm of their heart.
It will then charge itself to an appropriate power level and tell users that the person needs to be shocked.
If the patient does not need to be defibrillated, the automated external defibrillator will not allow a shock to be administered.
A button must still be pushed manually to trigger the shock, as the operator beforehand must be certain that nobody is touching the patient.
Often, automated external defibrillators will have speakers which give instructions when they are opened.
Current automated external defibrillator devices are designed for emergency medical technicians, home users, police and security officers and other people with minimal medical knowledge.
These devices are commonly found in large gathering places, such as airports, casinos, sports stadiums, and college campuses.
Electrode design
The most well-known type of electrode is the traditional metal paddle with an insulated handle.
This type must be held in place on the patient's skin while shocks are delivered.
Before the paddles are used, gel must be applied to the patient's skin so that there is a good connection and to minimise electrical resistance.
Another type of resuscitation electrode is designed as an adhesive pad which can be stuck onto the skin of a patient.
These electrodes are left connected to a defibrillator.
If defibrillation is required, the machine is charged, and the shock is delivered, without any need to apply any gel or to retrieve and place any paddles.
Both solid- and wet-gel adhesive electrodes are available.
Solid-gel electrodes are more convenient, because there is no need to clean the patient's skin after removing the electrodes.
However, the use of solid-gel electrodes presents a higher risk of burns during defibrillation, since wet-gel electrodes more evenly conduct electricity into the body.
Defibrillators are often depicted in movies, television, video games and other fictional media.
This is because it can quickly produce dramatic improvements in patient health.
Their function, however, is often exaggerated.
A curse is a word which threatens the other person to have bad luck.
Nobody knows if it really works or become true.
Some people believe in them even so, that they become true by magic.
For example, for fairy tales, the princes are cursed to become a beast or a frog (i.e. frog prince) by witches because of their bad behaviours.
But in the end a princess saves them.
There was also something called a "curse tablet" which Romans used to curse people they did not like.
They would often let them drift to the river so that the curse will be carried to where that person who has the curse.
But many curses are made when people are jealous and they want that person who has the curse to not do well.
Ventricular fibrillation (often shortened to VF or V-Fib) is a type of arrhythmia of the heart.
"Arrhythmia" means the heart is not beating normally.
What is Ventricular Fibrillation?
When a person is in ventricular fibrillation, the heart does not beat in any kind of pattern.
Instead, it quivers and twitches very quickly.
This problem is called "ventricular" fibrillation because it affects the ventricles of the heart.
The ventricles are the biggest parts of the heart.
Their job is to pump blood (which carries oxygen) to the lungs and the rest of the body.
When a person is in ventricular fibrillation, the ventricles cannot do this job.
This means that the lungs, brain, and other organs will not get enough blood or oxygen.
Ventricular fibrillation is a medical emergency.
Without enough blood and oxygen, no part of the body can survive.
If ventricular fibrillation continues for long enough, the blood will stop circulating around the body.
The person's breathing and heart will stop.
The person will die unless they get treatment quickly.
Ventricular fibrillation can be stopped by shocking the person with electricity from a defibrillator.
If a defibrillator is not available, CPR (cardiopulmonary resuscitation) should be done to keep the blood flowing until an ambulance comes or a defibrillator is available.
Doctors or paramedics can also give special medicines called anti-arrhythmic medicines, which can make the heart start beating normally again.
Some common anti-arrhythmic medicines are amiodarone and lidocaine.
If a person with ventricular fibrillation is treated right away, treatment is 90% successful (it works in 9 out of 10 people).
But treatment gets 10% less successful after every minute (so if treatment starts after one minute, it will work in only 8 out of 10 people.
After 5 minutes, it will work in only 4 out of 10 people.)
So getting treatment as soon as possible is very important.
If a person cannot be treated with medicine or a defibrillator right away, CPR will help keep blood and oxygen flowing through the person's body until treatment arrives.
In patients who are very likely to keep having ventricular fibrillation, a special defibrillator can be put into their chest by a surgeon.
(This special defibrillator is called an "implantable cardioverter-defibrillator.")
Any time the person goes into ventricular fibrillation, the defibrillator will give the person's heart an electric shock, to bring the heart back into a normal rhythm.
A marine mammal
a pinniped, a large ocean mammal.
There are three main groups:
Earless seals (or true seals)
Eared seals (or walking seals)
Seal hunting, both personal and commercial hunting of seals
Seal brown is a rich dark brown color RGB(50, 20, 20) (from the colour of dyed Fur seal fur)
Fixing or closing to give a tight fit
Seal (mechanical), a device to contain pressure.
Diaphragm seal, a flexible membrane that seals and isolates an enclosure
Symbol of authentication
Seal (device), a device used to produce an official stamp as a symbol of authority, or the impression left by a seal in sealing wax. (
Origin: Latin sigillum = "small symbol", a diminutive of signum)
Cylinder seal, cylinder engraved with a picture story, used in ancient times to roll an impression onto a sheet of wet clay
Great Seal of the United States used since 1782 to authenticate some documents issued by the United States government
Great Seal of the Realm, a British institution for authorising the monarch's official documents a personal signature
Great Seal of Scotland allows the monarch to authorise documents without signing
Imperial Seal of Japan, called 菊の御紋 in Japanese, meaning "Noble Symbol of Chrysanthemum"
Lord Privy Seal or Lord Keeper of the Privy Seal is one of the traditional sinecure offices of state in the United Kingdom
Knights Templar Seal used to validate documents approved by the order
Seal of Solomon, a legendary magical signet ring said to have belonged to King Solomon
LMLK seal, stamped on handles of large storage jars around Jerusalem about 700 BC
Nintendo Seal of Quality is a gold seal used by Nintendo to show that a game is properly licensed to run on their game consoles
As a person's name
Barry Seal (Adler Berriman Seal), pilot and drug smuggler turned DEA informant
Brajendra Nath Seal (born 1864), Indian philosopher of the Brahmo Samaj, Vice Chancellor of Visva Bharati University
David Seal (born 1972), an Australian football (soccer) player
Jaynie Seal (born 1973), an Australian television presenter
Lou Seal (Luigi Francisco Seal, Jr.), the official mascot of the San Francisco Giants team in Major League Baseball
Manuel Seal, a staff songwriter and producer at Jermaine Dupri's So So Def Recordings
Pu Tong Seal (1346 AD), legendary Burmese hero
Seal (musician) (Henry Olusegun Olumide Adeola Samuel), an Afro-European soul singer who has released three albums named "Seal":
Seal (1991 album)
Seal (1994 album)
Seal (2003 album)
As a place name
Seal Bay Conservation Park, on Kangaroo Island, South Australia
Seal Beach, a city in Orange County, California, United States of America
Naval Weapons Station Seal Beach, a United States Navy weapons and munitions loading, storage and maintenance facility in Seal Beach, California
Seal Island, a small islet about 5.7 km off the northern beaches of False Bay near Cape Town in South Africa
Seal Island (South Shetland Islands), a group of small islands and rocks lying 3 to 6 miles northwest of Elephant Island in the South Shetland Islands
Machias Seal Island at  under disputed sovereignty between the United States and Canada
Seal Island Bridge, an arch truss bridge crossing the Great Bras d'Or channel in Victoria County, Cape Breton Island, Nova Scotia
Seal Rock, a prominent rock offshore at the North end of Ocean Beach, San Francisco, United States
Seal Rocks, a small settlement in New South Wales, Australia
Seal, Kent, a village in Kent, England. (
Origin: probably Anglo-Saxon sēale = "copse of sallow-trees")
Seals, Georgia
As an acronym
United States Navy SEALs, special forces of the United States Navy. (
Origin: acronym from "SEa, Air, Land")
Advanced SEAL Delivery System, a midget submarine providing stealthy submerged transportation for special forces, primarily U.S. Navy SEALs
SEAL Recon Rifle, rifle developed to provide SEAL snipers with a portable, lightweight system with greater lethality
Semantics-directed Environment Adaptation Language, a computer programming language
SEAL (cipher), (Software-Optimized Encryption Algorithm), a fast cryptographic cipher
Safety Evidence Assurance Level, US government
SEAL (Computer Language), the Semantics-directed Environment Adaptation Language
SEAL (Sea Scout Leadership Training), a leadership training course for Sea Scouts youth in the Boy Scouts of America
Software Engineering and Ada Lab, NASA
HMS Seal (N37), a submarine of the Royal Navy
USS Seal has been used as the name of two submarines of the United States Navy
Red seal ships (朱印船), Japanese armed merchant sailing ships with a red-sealed patent (early 17th century)
In computers
SEAL GUI, an open source Graphical User Interface for DOS
Tachycardia is the fast beating of the heart.
In adults, it refers to heart rates higher than 100 beats per minute.
Tachycardia may be a normal physiological response to stress, but depending on the cause and how healthy the patient is, tachycardia could be harmful and need medical treatment.
In some cases, tachycardia can cause death.
Tachycardia can be harmful in two ways.
First, when the heart beats too rapidly, it may perform inefficiently.
Second, the faster the heart beats, the more oxygen and nutrients the heart requires.
This can be especially problematic for patients suffering from ischaemic heart disease.
The word fracture is often applied to bones of living creatures or to crystals or crystalline materials, such as gemstones or metal.
Sometimes, fractures can happen without the object actually separating into two or more pieces.
Shear stress is a stress state where the stress is parallel to the surface of the material, as opposed to normal stress when the stress is perpendicular to the surface.
Shear stress is relevant to the motion of fluids upon surfaces, which result in the generation of shear stress.
Scissors work by shear stress
Tension (mechanics), in physics, a force related to the stretching of an object
High-tension line, sometimes used to refer to electrical voltage
Stress (biology), physiological or mental stress
Tension (music), the perceived need for relaxation or release created by a listener's expectations
Suspense, in a dramatic work, leaving the audience feeling uncertain and interested about the outcome of certain actions
Tenseness, in phonetics, describes a certain sound quality
Tension (band), a rock band
Tensile stress
Tensile architecture
Tension is a reaction force applied by a stretched string (rope or a similar object) on the objects which stretch it.
The direction of the force of tension is parallel to the string, towards the string.
Tension exists also inside the string itself: if the string is made up of two parts, tension is the force which the two parts of the string apply on each other.
The amount of tension in the string determines whether it will break, as well as its vibrational properties, which are used in musical instruments.
Force (physics)
Stress (physics)
Bias (textile), in clothing design, fabric may be cut on the shear
Cosmic shear, an effect of distortion of image of distant galaxies due to deflection of light by matter, as predicted by general relativity (see also weak lensing and gravitational lens)
Geological shear, a form of fault
Guillotine (metalwork), also called a shear, a machine used to cut sheet metal
Shear line (locksmithing), in lockpicking, where the inner cylinder ends and the outer cylinder begins in a cylinder lock
Shear line (meteorology), an area of wind shear
Shear (mathematics), a particular kind of linear mapping, also called transvections
Shear stress in physics, refers to a stress state that will cause shearing (see verb below) when it exceeds a material's shear strength,
Wind shear, a difference in wind speed or direction between two wind currents in the atmosphere
Sheep shearing, the process of removing the wool from a sheep
Shearing interferometer, in optics, a simple and very common means to check the collimation of beams by observing interference
Shearing (physics), the deformation of a material substance in which parallel internal surfaces slide past one another,
Skin, specifically, the tearing and splitting of the layers
Flow, another name for "flux" in physics, which is the rate at which something travels through a given cross section
In fluid mechanics, the word flow is often used to mean a complete description of the motion of a fluid.
See also volumetric flow rate
In circulatory physiology, the word flow (e.g. of blood or lymph fluid) is commonly used as shorthand for regional flow, i.e., flow standardised to the volume or mass of a region of tissue under study (SI units: mL/s/mL or mL/s/g)
Flow cytometry, abbreviated "flow", in certain laboratory applications, is a technique for counting, examining and sorting microscopic particles suspended in a stream of fluid
Environmental flow, in ecology, the discharge or level of water necessary in a river or water source to sustain a healtly ecosystem
Dataflow and workflow, terms that describe the flow of data in a mostly non-linear succession of computing steps
Flow (mathematics), the one-dimensional (continuous, differentiable) action of a group, usually arising in the solution of differential equations
Examples include geodesic flow, Hamiltonian flow and Anosov flow
Network flow, an assignment of flow to the edges of a directed graph in graph theory
Flow (psychology), the feeling of complete and energized focus in an activity, with a high level of enjoyment and fulfillment (a concept popularised by the book Flow by Mihaly Csikszentmihalyi)
Flow (television), in television studies and programming, the sequence of television material from one element to the next
Flow (journal), an online journal of television and media studies
FLOW (band), a J-Pop group
Flow binding system, abbreviated "flow", a US based manufacturer of proprietary snowboard bindings*flOw, a Flash game that will be available on the PlayStation 3
Flow, the total value of sales or purchases in an accounting period, usually a quarter or a year in economics and accounting
"Flow", in hip hop and poetry, a verb or noun described as the ability to start and maintain a verse of lyrics
"Flow", the section of a skatepark which is meant to be ridden without pushing, usually consisting of banks, hills, funboxes, etc.
I.O.U. means "I Owe You" or "I Owe Unto".
It is a note between two people that is used to say that one person owes something to the other.
It is usually used for money.
I.O.U.'s are most often only used between people that know each other very well, for example, friends.
Types of deformation
Elastic deformation
This type of deformation is reversible.
Once the forces are no longer applied, the object returns to its original shape.
As the name implies, elastic (rubber) has a rather large elastic deformation range.
The thermoplastics and metals have moderate elastic deformation ranges while ceramics, crystals, and hard thermosetting polymers undergo almost no elastic deformation.
Malleable materials do not undergo elastic deformation.
Metal fatigue
A phenomenon only discovered in modern times is metal fatigue, which occurs primarily in ductile metals.
It was originally thought that a material deformed only within the elastic range returned completely to its original state once the forces were removed.
However, faults are introduced at the molecular level with each deformation.
After many deformations, cracks will begin to appear, followed soon after by a fracture, with no apparent plastic deformation in between.
Depending on the material, shape, and how close to the elastic limit it is deformed, failure may require thousands, millions, billions, or trillions of deformations.
Plastic deformation
This type of deformation is not reversible.
But an object in the plastic deformation range will first have undergone elastic deformation, which is reversible, so the object will return part way to its original shape.
Soft thermoplastics have a rather large plastic deformation range as do ductile metals such as copper, silver, and gold.
Steel does, too, but not iron.
Hard thermosetting plastics, rubber, crystals, and ceramics have minimal plastic deformation ranges.
Perhaps the material with the largest plastic deformation range is wet chewing gum, which can be stretched dozens of times its original length.
This type of deformation is also not reversible.
A break occurs after the material has reached the end of the elastic, and then plastic, deformation ranges.
At this point forces accumulate until they are sufficient to cause a fracture.
A popular misconception is that all materials that bend are "weak" and all those which do not are "strong".
In reality, many materials which undergo large elastic and plastic deformations, such as steel, are able to absorb stresses which would cause brittle materials, such as glass, with minimal elastic and plastic deformation ranges, to break.
There is even a story to describe this observation (paraphrased below):
"The mighty oak stands strong and firm before the wind, while the willow yields to the slightest breeze.
However, in the strongest storm, the oak will break while the willow will bend, and thus survive.
So, in the end, which is the stronger of the two ?"
Ceramic is the name for some materials that are formed by the use of heat.
The word ceramic comes from the Greek word  ().
Chemically, it is an inorganic compound of  metal, non-metal or metalloid atoms held together by chemical bonds.
Up to the 1950s or so, the most important were the traditional clays, made into pottery, bricks, tiles and the like, also cements and glass.
Clay-based ceramics are described in the article on pottery.
A composite material of ceramic and metal is known as cermet.
The word ceramic can be an adjective, and can also be used as a noun to refer to a ceramic material, or a product of ceramic manufacture.
Ceramics may also be used as a singular noun referring to the art of making things out of ceramic materials.
The technology of manufacturing and usage of ceramic materials is part of the field of ceramic engineering.
Many clay-based ceramic materials are hard, porous, and brittle.
The study and development of ceramics includes methods to deal with these characteristics, to accentuate the strengths of the materials and investigate novel applications.
Types of ceramic materials
Structural, including bricks, pipes, floor and roof tiles
Refractories, such as kiln linings, gas fire radiants, steel and glass making crucibles
Whitewares, including tableware, wall tiles, decorative art objects and sanitary ware
Technical ceramics is also known as engineering, advanced, special, and in Japan, fine ceramics.
Such items include tiles used in the Space Shuttle program, gas burner nozzles, bullet-proof vests, nuclear fuel uranium oxide pellets, bio-medical implants, jet engine turbine blades, and missile nose cones.
Frequently the raw materials do not include clays.
Examples of ceramics
'Hard-paste' porcelain, fired at a higher temperature.
'Soft-paste' porcelain, fired at a lower temperature: Bone china
Earthenware, which is often made from clay, quartz and feldspar
Classification of technical ceramics
Oxides: alumina, zirconia
Non-oxides: carbides, borides, nitrides, silicides
Composites: particulate reinforced, combinations of oxides and non-oxides
Properties of ceramics
Mechanical properties
Ceramic materials are usually crystalline (having a repeating shape) or amorphous (no repeating shape).
They are usually held together with covalent or ionic bonds.
Thus, they tend to fracture (break) before any plastic deformation (permanent damage) happens.
So they have poor toughness (resistance to breaking).
Second, ceramics have pores (small holes) which focus stress on smaller areas.
This decreases the toughness even more and reduces the tensile strength.
For these two reasons, ceramics fail far more catastrophically (suddenly) than metals.
Crystalline materials are stiff; there are few places where the deformation can spread.
So the deformation is very slow.
In amorphous materials, viscous flow is the main source of plastic deformation.
Electrical properties
Some ceramics are semiconductors.
Most of this type of ceramic are "II-VI semiconductors", which are a combination of an alkaline earth or Group 12 metal and a non-metal from Group 16.
A major example of these is zinc oxide.
Some people are thinking about making blue LEDs from zinc oxide.
But ceramic researchers focus on electrical properties that affect boundaries between individual grains.
One of the most common examples of this is the varistor.
Semiconducting ceramics are also used as gas sensors.
Semiconducting ceramics are also employed as gas sensors.
When we pass gases over a polycrystalline ceramic, its electrical resistance changes.
If we know the possible gas mixtures, we can produce very cheap devices.
Under some conditions, such as extreme cold temperatures, some ceramics show superconductivity.
We do not know the exact reason.
But we have discovered two major families of superconducting ceramics.
Piezoelectricity, pyroelectricity, and ferroelectricity
Piezoelectricity is an electric charge caused by mechanical stress.
It appears in many ceramic materials, such as quartz.
We use quartz to measure time in watches and other electronics.
This kind of device turns electricity into mechanical motions and back, making a stable oscillator.
The piezoelectric effect is generally stronger in materials that also show pyroelectricity. (
Pyroelectricity is the ability of a material to generate electricity if its temperature changes.)
All pyroelectric materials are also piezoelectric.
We can use these materials to convert between thermal, mechanical, and electrical energy.
For instance, we can put a pyroelectrical crystal in a furnace.
If we take out and let it cool without applying any force to it, it will generate a large static charge.
This type of crystal is most common in motion sensors.
That is because the tiny rise in temperature from a warm body entering a room is enough to produce a voltage in the crystal.
A motion sensor reads that voltage and converts it to data.
In turn, pyroelectricity is strongest in materials which also display the ferroelectric effect.
This is when we can reverse or move a stable electric polarization by applying an electrostatic field.
If a material is ferroelectric, it is also pyroelectric.
We use this effect to store information in ferroelectric capacitors and random-access memory.
The most common piezoelectric materials are lead zirconate titanate and barium titanate.
We use them for high-frequency loudspeakers, sonar, and atomic-force and scanning-tunneling microscopes.
Grain-boundary insulation at critical temperatures
In some semiconducting ceramics a gain in temperature causes grain boundaries to become insulating.
This is most common in mixtures of heavy metal titanates.
We can adjust the transition temperature (the temperature at which this happens) over a wide range by changing the chemistry.
In this kind of material, current passes through the material until it reaches the transition temperature, at which point the circuit breaks and current flow stops.
We use these ceramics as self-controlled heating elements in, for example, rear-window defrosting circuits in cars.
At the transition temperature, the material's dielectric response approaches infinity.
We cannot use the material near its critical temperature because it is hard to control temperature at that range.
Despite this, the dielectric effect remains strong even at much higher temperatures.
For this reason as well as because of how low their critical temperatures are, we use titanates as ceramic capacitors.
Classification of ceramics
Non-crystalline ceramics, being glasses, tend to be formed from melts.
The glass is shaped when either fully molten, by casting, or when in a state of toffee-like viscosity, by methods such as blowing to a mold.
If later heat-treatments cause this class to become partly crystalline, the resulting material is known as a glass-ceramic.
Crystalline ceramic materials are not amenable to a great range of processing.
Methods for dealing with them tend to fall into one of two categories – either make the ceramic in the desired shape, by reaction in situ, or by "forming" powders into the desired shape, and then sintering to form a solid body.
Ceramic forming techniques include shaping by hand (sometimes including a rotation process called "throwing"), slip casting, tape casting (used for making very thin ceramic capacitors, etc.),
injection molding, dry pressing, and other variations. (
See also Ceramic forming techniques.
Details of these processes are described in the two books listed below.)
In situ manufacturing
The most common use of this method is in the production of cement and concrete.
Here, the dehydrated powders are mixed with water.
This starts hydration reactions, which result in long, interlocking crystals forming around the aggregates.
Over time, these result in a solid ceramic.
The biggest problem with this method is that most reactions are so fast that good mixing is not possible, which tends to prevent large-scale construction.
However, small-scale systems can be made by deposition techniques, where the various materials are introduced above a substrate, and react and form the ceramic on the substrate.
This borrows techniques from the semiconductor industry, such as chemical vapour deposition, and is very useful for coatings.
Sintering-based methods
The principles of sintering-based methods is simple.
Once a roughly held together object (called a "green body") is made, it is baked in a kiln, where diffusion processes cause the green body to shrink.
The pores in the object close up, resulting in a denser, stronger product.
The firing is done at a temperature below the melting point of the ceramic.
There is virtually always some porosity left, but the real advantage of this method is that the green body can be produced in any way imaginable, and still be sintered.
This makes it a very versatile route.
There are thousands of possible refinements of this process.
Some of the most common involve pressing the green body to give the densification a head start and reduce the sintering time needed.
Sometimes organic binders such as polyvinyl alcohol are added to hold the green body together; these burn out during the firing (at 200–350 °C).
Sometimes organic lubricants are added during pressing to increase densification.
It is not uncommon to combine these, and add binders and lubricants to a powder, then press. (
The formulation of these organic chemical additives is an art in itself.
This is particularly important in the manufacture of high performance ceramics such as those used by the billions for electronics, in capacitors, inductors, sensors, etc.
The specialized formulations most commonly used in electronics are detailed in the book "Tape Casting," by R.E. Mistler, et al.,
Ceramic Soc. [
Westerville, Ohio], 2000.)
A comprehensive book on the subject, for mechanical as well as electronics applications, is "Organic Additives and Ceramic Processing," by D. J. Shanefield, Kluwer Publishers [Boston], 1996.
A slurry can be used in place of a powder, and then cast into a desired shape, dried and then sintered.
Indeed, traditional pottery is done with this type of method, using a plastic mixture worked with the hands.
If a mixture of different materials is used together in a ceramic, the sintering temperature is sometimes above the melting point of one minor component – a liquid phase sintering.
This results in shorter sintering times compared to solid state sintering.
Other applications of ceramics
Some knives are ceramic.
The ceramic knife blade will stay sharp for much longer steel will, although it is more brittle and can be snapped by dropping it on a hard surface.
Ceramics such as alumina and boron carbide have been used in body armor to repel bullets.
Similar material is used to protect cockpits of some military airplanes, because of the low weight of the material.
Ceramic balls can be used to replace steel in ball bearings.
Their higher hardness makes them last thrice as long.
They also deform less under load meaning they have less contact with the bearing retainer walls and can roll faster.
In very high speed applications, heat from friction during rolling can cause problems for metal bearings; problems which are reduced by the use of ceramics.
Ceramics are also more chemically resistant and can be used in wet environments where steel bearings would rust.
The major drawback to using ceramics is high cost.
In the early 1980s, Toyota researched an adiabatic ceramic engine which can run at a temperature of over 6000 °F (3300 °C).
Ceramic engines do not require a cooling system and hence allow a major weight reduction and therefore greater fuel efficiency.
Fuel efficiency of the hotter engine is also higher by Carnot's theorem.
In a metallic engine, much of the energy released from the fuel must be dissipated as waste heat so it won't melt the metallic parts.
Despite all of these desirable properties, such engines are not in production because the manufacturing of ceramic parts in the requisite precision and durability is difficult.
Imperfection in the ceramic leads to cracks, which can wreck the engine, possibly by explosion.
Mass-production is not feasible with current technology.
Ceramic parts for gas turbine engines may be practical.
Currently, even blades made of advanced metal alloys used in the engines' hot section require cooling and careful limiting of operating temperatures.
Turbine engines made with ceramics could operate more efficiently, giving aircraft greater range and payload for a set amount of fuel.
Bio-ceramics include dental implants and synthetic bones.
Hydroxyapatite, the natural mineral component of bone, has been made synthetically from a number of biological and chemical sources and can be formed into ceramic materials.
Orthopedic implants made from these materials bond readily to bone and other tissues in the body without rejection or inflammatory reactions.
Because of this, they are of great interest for gene delivery and tissue engineering scaffolds.
Most hydroxyapatite ceramics are very porous and lack mechanical strength and are used to coat metal orthopedic devices to aid in forming a bond to bone or as bone fillers.
They are also used as fillers for orthopedic plastic screws to aid in reducing the inflammation and increase absorption of these plastic materials.