Aarushhh/wikipedia-simple-splitted huggingface dataset:
Many composers from the Classical, Romantic and 20th century classical music periods wrote sets of variations. Wolfgang Amadeus Mozart wrote several, one of which was based on a French folktune which we know in Britain as “Twinkle, Twinkle, Little Star”.  Beethoven wrote several wonderful sets of variations.  Many of them were for piano, but he also used the form in other pieces e.g. the slow movement of his Ninth Symphony.  Schubert often wrote variations on tunes from his own songs.

Other composers who wrote variations include Brahms, Elgar, Schoenberg, and Britten.
Musical forms
The article about graphical symbols is at Logo
Logo is a programming language that is easy to learn. It is used to teach students and children to program a computer. It was developed to process lists of words. It was like the language LISP.

History
In 1967, the first Logo ran on a mainframe computer, a machine called a teletype was used to type in and printout the results. There was no screen.

In 1969, it was used to control a Floor Turtle. Commands were added to send the turtle forwards and backwards, and to turn the turtle to left or right. This turtle had pen with different colors. When it moved, it left a trail on the floor.

Versions
When a new version of Logo was developed to draw graphics on a screen, it used the same commands. This was called Turtle graphics.

There are 170 versions of Logo. Many of them are open source and free. There are three Logo textbooks that can be downloaded free. Logo is usually an interpreted language.

Examples
Examples

Hello World 
Load the Logo program. Type the next line in the command box.

 print [Hello World!]

The computer replies.

 Hello World!

Example Showing Graphics and Functional Programming 
A spiral drawn using recursion. 
Using the editor, type in this new definition.
 to spiral :size
    if  :size > 30 [stop] ; a condition stop
    fd :size rt 15        ; many lines of action
    spiral :size *1.02    ; the tailend recursive call
 end
Type this in the command box.
 spiral 10

On the screen you will see.

Other websites 
Logo Programs
MSWLogo For Windows
FMSLogo For Windows
Berkeley Logo (UCBLogo)
Microworlds Microworlds, a commercial Logo for Mac and Windows
Elica  a 3D Logo for Windows
Lhogho a Logo compiler for Linux and Windows
 Surf Your Logo Code A modern web based Logo interpreter using HTML5 and JQuery.
MaLT (Machine Lab Turtlesphere) A web based 3D Logo application with the feature of dynamic manipulation (developed in HTML5 & three.js).
Online books
A Logo Tutorial  for the OLPC project
The Great Logo Adventure, Jim Muller A book for children.
Computer Science Logo Style, Brian Harvey, MIT Press (3 volumes) , , . Advanced books.

References 

Programming languages
Lisp (used to be called LISP) is a programming language. It is among the oldest programming languages that are still used today. Only Fortran is one year older. Lisp was designed by John McCarthy in 1958. The best-known versions of LISP are Common Lisp, Scheme and Clojure. Many concepts that are used in modern programming languages were first created in Lisp.
Linked lists are a very important data structure in Lisp. 
The basic concepts behind Lisp are easy to learn. Logo is another version of Lisp that was made for children. Logo can help young children develop skills and become efficient within the programming language.

Simple examples (Scheme) 
In Lisp, operations are written in prefix notation, and they start and end with parentheses. For example, the formula  is written as:

(/ (+ 3 5) 4)
; returns 2
Because Lisp is a functional language, Lisp programs often use recursion to solve problems. Here is a Scheme program that finds the factorial of a number. The function (factorial n) starts by testing if  or not. If , then (factorial 0) is 1. If , then (factorial n) returns the product of  and the factorial of .

(define (factorial n)
    (if
      (= n 0)
      1
      (* n (factorial (- n 1)))))

(factorial 6)
; returns the factorial of 6: 6! = 6*5*4*3*2*1 = 720

Linked lists are an important idea in Lisp. The list without any things in it is known as the empty or nil list, and is written as '(). A list that has things in it is written as '(dog cat). 

The operation car is used to get the first thing of a list. For example,

(car '(dog cat fish))
; returns 'dog, which is the first thing in the list
(car '(1 2 3 4 5 6 7))
; returns 1
(car '())
; this code gives an error because the list is empty/nil
The operation cdr returns everything in the list except for the first thing.
(cdr '(dog cat fish))
; returns '(cat fish)
(cdr '(6))
; returns '(), because there is nothing in the list after the first thing (6)
(cdr '())
; gives an error because the list is empty/nil

Here is a hello world program in Scheme:

(display "Hello world!")

Programming languages
Lambda calculus can be called the smallest universal programming language. At its core, lambda calculus is made up of just one transformation rule (something called variable substitution) and just one way to define a function. Each function definition has a list of the function's parameters, which are all of the variables that can be used in that function. Variable substitution is where specific variables in a function are replaced by other values (for example, the value  could take the place of every spot in a function where the variable  appears). This is called a transformation rule because it can be used to transform lambda expressions by changing around their values.
There is no way to answer the question of whether two lambda calculus expressions are the same as each other (in more specific words, there is no general algorithm that can show that two lambda expressions are equivalent). This was the first problem where the idea of undecidability could be proven. Later, undecidability was also proven for the halting problem, where it was shown that there is no general way to show whether or not a program will keep running forever. Lambda calculus has had large effects on lots of functional programming languages, such as LISP, ML, and Haskell.

Calculus
Recursion
Family Jewels is a two disc compilation DVD by the Australian hard rock band AC/DC. It contains videos from the Bon Scott era to the Brian Johnson era. The compilation was released in 2005.

Track listing Disc 1 
Baby, Please Don't Go
Show Business
High Voltage
It's A Long Way To The Top (If You Wanna Rock 'N' Roll)
TNT
Jailbreak
Dirty Deeds Done Dirt Cheap
Dog Eat Dog
Let There Be Rock
Rock 'N' Roll Damnation
Sin City
Riff Raff
Fling Thing/Rocker
Whole Lotta Rosie
Shot Down In Flames
Walk All Over You
Touch Too Much
If You Want Blood (You've Got It)
Girls Got Rhythm
Highway To Hell

Track listing Disc 2 
Hells Bells
Back In Black
What Do You Do For Money Honey
Rock And Roll Ain't Noise Pollution
Let's Get It Up
For Those About To Rock (We Salute You)
Flick Of The Switch
Nervous Shakedown
Fly On The Wall
Danger
Sink The Pink
Stand Up
Shake Your Foundations
Who Made Who
You Shook Me All Night Long
Heatseeker
That's The Way I Wanna Rock 'N' Roll
Thunderstruck
Moneytalks
Are You Ready

Music videos and DVDs
Power transmission is moving energy from where it is made to where it is used.

Power is defined formally as units of energy per unit time.
In SI units: 1 watt = 1 joule/s = 1 newton * metre/second (1W=1J/s=1N·m/s).

Electrical power 

With widespread establishment of power grids, power transmission has came to be associated most often with electric power transmission.

Mechanical power 

Electrical power transmission has replaced mechanical power transmission in all but the very shortest distances. From the start of the industrial revolution until the end of the 19th century mechanical power transmission was the norm. Factories were fitted with overhead driveshafts providing rotary power. Drivebelts would provide power to individual machines on the shop floor.

Mechanical power may be transmitted directly using a solid structure such as a driveshaft; transmission gears can adjust the amount of torque or force vs. speed in much the same way an electrical transformer adjusts voltage vs current.
Chemicals and fuels
Chemical energy is transmitted by moving fuels to generate power in distant places. Pipelines and other large infrastructure projects transport natural gas, petroleum and petroleum products for use as fuel. 

Energy
Ocean surface waves are surface waves that occur in the upper layer of the ocean. They usually result from wind. Some are made by geologic effects like earthquakes or vulcanicity and may travel thousands of miles before striking land. They range in size from small ripples to huge tsunamis. There is little actual forward motion of individual water particles in an unbroken wave, despite the large amount of energy and momentum it may carry forward. When a wave hits shallow water, it "breaks" because the bottom moves more slowly than the top.

Wave formation  

The great majority of large breakers one sees on an ocean beach result from distant winds. Three factors influence the formation of these "wind waves":

 Wind speed
 Distance of open water that the wind has blown over.
 Length of time the wind has blown over a given area. 

All of these factors work together to determine the size and shape of ocean waves. The greater each of the variables, the larger the waves. Waves are measured by:
Height (from trough to crest)
 Wavelength (from crest to crest)
 Period (time interval between arrival of consecutive crests at a stationary point) 

Waves in a given area typically have a range of sizes. For weather reporting and for scientific analysis of wind wave statistics, their size over a period of time is usually expressed as "significant wave height." This figure represents the average height of the highest one-third of the waves in a given time period (usually twelve hours) or in a specific storm system or event.  Given the variability of wave size, the largest individual waves are likely to be twice the reported significant wave height for a particular day or storm.

References 

 "Anatomy of a Wave" Holben, Jay boatsafe.com captured 5/23/06
 Carr, Michael "Understanding Waves" Sail Oct. 1998: 38-45.
 Rousmaniere, John. The Annapolis Book of Seamanship, New York: Simon & Schuster 1989
 National Weather Service
Other websites 
 Introductory oceanography chapter 10 - Ocean Waves 
 Understanding waves waves, storm, tsunamis, seiches, bores, deadwater, etc. (18pp)
 HyperPhysics - Ocean Waves
 SHOM - in French 
 Water Waves Wiki 
 Wave equation 
 Waverider Buoys for South East Queensland  
 Costalwatch.com : Australian Wave Prediction for Surfers Website

Oceanography
A crest is the point on a wave with the greatest positive value or upward displacement in a cycle. A trough is the opposite of a crest.

When the crest and the trough of two waves of equal magnitude and frequency intersect or collide when in phase with each other the result is called constructive interference and the magnitudes double (above and below the line), when 180° out of phase the result is destructive interference with each other the resulting wave is the undisturbed line that is in the middle of the diagram having zero amplitude.

In other words, the wave crest is called a peak.

Related pages
 Ocean surface wave

References
, 704 pages.

Wave physics
A trough is a box-like drinking vessel for farm animals.  Other senses of the word refer to things that are lower than their surroundings, like a trough:

 Trough (physics)
 Trough (meteorology);
 Trough (geology);
 a trough is also a noticeable and statistically recordable decline in an economy or graph.
 in chemistry it can be a Langmuir Blodgett Trough

See also trow.
In physics, a surface wave can refer to a mechanical wave that propagates along the interface between differing media, usually two fluids with different densities.  A surface wave can also be an electromagnetic wave guided by a refractive index gradient.  For radio waves, a ground wave is a surface wave that propagates close to the surface of the Earth.

Related pages

Waves 
 Ocean surface waves, internal waves and crests, dispersion, and freak waves
 List of wave topics

People 
Arnold Sommerfeld – published the mathematical treatise on the zenneck wave

Other articles, further reading, and references
Other websites 
 Eric W. Weisstein, et al., "Surface Wave", Eric Weisstein's World of Physics, 2006.
 "Surface waves ". Integrated Publishing (tpub.com).
 Brett Ketter, "Surface Wave Theory ". University of Wisconsin - Milwaukee.
 David Reiss, "Electromagnetic surface waves". The Net Advance of Physics: Special Reports, No. 1
 Gary L. Peterson, "Rediscovering the Zenneck wave". Feed Line No. 4. (ed. reproduction available online at Twenty First Century Books)

Standards and doctrines
 "Surface wave ". Telecom Glossary 2000, ATIS Committee T1A1, Performance and Signal Processing, T1.523-2001.
 "Surface wave ", Federal Standard 1037C.
 "Surface wave", MIL-STD-188
 "Multi-service tactics, techniques, and procedures for the High-Frequency Automatic Link Establishment (HF-ALE): FM 6-02.74; MCRP 3-40.3E; NTTP 6-02.6; AFTTP(I) 3-2.48; COMDTINST M2000.7" Sept., 2003.
Books
 Waldron, Richard Arthur, "Theory of guided electromagnetic waves". London, New York, Van Nostrand Reinhold, 1970.  LCCN 69019848 //r86
 Weiner, Melvin M., "Monopole antennas" New York, Marcel Dekker, 2003. 
 Budden, K. G., "The wave-guide mode theory of wave propagation". London, Logos Press; Englewood Cliffs, N.J., Prentice-Hall, c1961. LCCN 62002870 /L
Journals and papers
Wait
 Wait, J. R., "Lateral Waves and the Pioneering Research of the Late Kenneth A Norton".
 Wait, J. R., and D. A. Hill, "Excitation of the HF surface wave by vertical and horizontal apertures". Radio Science, 14, 1979, pp 767–780.
 Wait, J. R., and D. A. Hill, "Excitation of the Zenneck surface by a vertical aperture", Radio Science, 13, 1978, pp. 967–977.
 Wait, J. R., "A note on surface waves and ground waves", IEEE Transactions on Antennas and Propagation, Nov 1965. Vol. 13, Issue 6, pg 996- 997 ISSN 0096-1973
 Wait, J. R., "The ancient and modern history of EM ground-wave propagation". IEEE Antennas Propagat. Mag., vol. 40, pp. 7–24, Oct. 1998.
 Wait, J. R., "Appendix C: On the theory of ground wave propagation over a slightly roughned curved earth", Electromagnetic Probing in Geophysics. Boulder, CO., Golem, 1971, pp. 37–381.
 Wait, J. R., "Electromagnetic surface waves", Advances in Radio Research, 1, New York, Academic Press, 1964, pp. 157–219.
Other media
  L.A. Ostrovsky (ed.), "Laboratory modeling and theoretical studies of surface wave modulation by a moving sphere", Environmental Technology Laboratory, U.S. Dept. of Commerce, National Oceanic and Atmospheric Administration, Oceanic and Atmospheric Research Laboratories, 2002. OCLC 50325097

Mechanics
Nausea is a general feeling of unease and discomfort in the stomach, often with the urge to vomit. The word nausea comes from the Latin word for seasickness.

Nausea is a symptom, rather than an illness or disease. The causes for it very often are not in the stomach itself, but somewhere else in the body. Nausea is often caused by a stomach virus. Nausea is usually harmless, in the short term. A good treatment for it can be not to take solid food (and to only drink non-alcoholic drinks, like water). Nausea can also occur during pregnancy, and is quite normal in that context. People can suffer nausea without vomiting.

References 

Symptoms
Anxiety is distress or uneasiness of mind caused by a fear of danger or misfortune.  Very often, people with anxiety also feel worries. There can also be physical symptoms, like having a headache or an upset stomach.

Anxiety is a very common human emotion and is often associated with fear, panic, and the fight or flight response. The amount of stress needed to cause anxiety will vary from person to person however, basics include: losing one's job, the death of a loved one, or an accident, to name a few. In most people, anxiety will settle over time and one will return to normal state.  

Some people suffer a lot of anxiety over a long period of time which controls them and makes their lives difficult. These conditions are called anxiety disorders and can be treated by therapy and medicine.
General anxiety symptoms are things such as; continual tiredness / exhaustion, inability to relax, lack of confidence, low self-esteem, fear of public places, fear of socialising, frequent feelings of irrational anxiety / fear, compulsive behavior, worrying about making mistakes, regular nightmares, disturbed sleep patterns, excessive crying, headaches, stomach problems, diarrhea, nausea, aching muscles, and so on.

Symptoms of anxiety attacks are things like; sweating, shaking and tremors, palpitations, shortness of breath, hyperventilating, racing heart beat, tingling in hands and feet, feeling of impending doom, feeling you are having a heart attack. There are more, but these are the usual ones.

Medicine 
These symptoms, more or less, define anxiety but they can also be signs of other problems, so the first port of call has to be a doctor or other health care professional. They will be able to define what the problem is exactly, and propose the appropriate treatment.
A doctor’s first line treatment is usually through drug-based medication; for example antidepressants, anti-anxiety tablets and beta blockers. These can be very effective, but they all have side effects, some worse than others. This can tend to put folks off continuing with them.  Note however, that many drugs that have been taken for a longer time, need to be stopped in a special way (usually, with the help of a doctor); simply stopping the drug can lead to withdrawal symptoms. 

Other non-drug therapies are becoming popular such as; self-hypnosis, meditation, yoga, cognitive behavioral therapy, counseling, acupuncture, etc. These are therapies to help people ‘manage’ or ‘cope’ with their anxiety and / or anxiety attacks.

But what about the underlying cause(s) of anxiety? The two treatment types above focus on either reducing the symptoms of anxiety, or, helping a person cope with their disorder. They don’t seem to do anything about the underlying condition(s) that are causing the anxiety.
And the very ‘fear’ of another anxiety attack can bring one on. As long as this irrational fear exists it’s very difficult to stop attacks and resolve the general anxiety. Eliminating this fear can prevent further attacks and get rid of the general anxiety much more effectively.

Anxiety disorders 
Anxiety disorders are any sort of disorder caused by a major amount of anxiety. There are many different disorders, each of which may be diagnosed by a trained professional. Examples of such disorders are
Brain-based disorders
Obsessive-Compulsive Disorder: is when someone is obsessed with intrusive (unwanted) thoughts that cause the person do to certain actions (compulsions) they don't want to do but feel forced to do it otherwise they feel like something bad will happen to them or the thoughts will not go away unless they respond to them by doing rituals. 
Post-Traumatic Stress Disorder: is when someone has a very hard time trying to get over a very scary event that happened to them in the past and when they think of it, causes them anxiety attacks. For example, someone with PTSD has been in a car crash earlier in their lives and avoid driving or riding on cars and instead prefer to walk, take the train, or sometimes ride a bus to feel safe.
Fear of specific things 
 Fear of certain animals: Arachnophobia is the fear of spiders 
 Fear of certain situations: Agoraphobia is the fear of crowds (and of not being able to get away easily), Acrophobia is the fear of heights 
 Fear of bridges: Gephyrophobia is the fear of bridges which people who have it often driving on bridges, or if they are riding as a passenger, will be very anxious if the driver crosses them on a bridge.
 Generalised ones, such as Post-traumatic stress disorder (which occurs in people who have often been exposed to stressful situations, such as wars).
There are many more that are not listed here. See List of phobias for more.

General
 Generalised Anxiety Disorder is excessive worry about many things.
 Panic Disorder is when a person suffers from random panic attacks, it can often lead to agoraphobia.

Non-medical, religious treatments 
The state of anxiety can be calmed with the devotion of the Rosary that allows the person to pray and meditate with a great sense of peace.
Related pages 
 Depression (mood)
 Depression (mental illness)
 Existentialism

References 

Anxiety disorders
A lumbar puncture (often called spinal tap, by non-doctors) is a medical method to collect a sample of cerebrospinal fluid (fluid from the brain). This can be done to analyse the sample, to find some hints to diseases. It can also be done to lower the pressure of the fluid inside the skull.

Medical procedures

ja:脳脊髄液#脳脊髄液を使った検査
Wave power means the use of ocean surface waves and the capture of that energy to do useful work—including electricity generation, desalination, and the pumping of water (into reservoirs). It makes use of the kinetic energy of the waves that are driven by the wind.

Power from ocean surface wave motion might produce much more energy than tides. Tests have shown that it is possible to produce energy from waves, particularly in Scotland in the UK. But the technology is not as well developed as other renewable energy such as wind power or solar power.

Other websites 
 Practical Ocean Energy Management Systems Inc Links and discussion 
 An Ocean Wave Energy Converter Using Rotors 
 Oceanography: waves
 "Waves" by Tim Lovett  -- Tables and trivia on waves
 Wave Energy  -- World Energy Council
 Corvallis Gazette Times -- Oregon State University wants to host a national wave research center

Hydropower
Port Royal was a city in Jamaica. It was the focus of trade in Jamaica in the 17th century. It was known for its piracy, but also for the riches accumulated, and for the very bad moral values that could be found in the city. An earthquake in June of 1692 largely destroyed the city. Two thirds of the city sank into the Caribbean Sea. Today, the city is covered by at least 8 metres of water. The city is among the most important archaeological sites in the Ocean. Its role as a center for trade was taken over by Spanish Town, Jamaica, and later by Kingston.

Settlements in Jamaica
S.T.A.L.K.E.R.: Shadow of Chernobyl, previously known as S.T.A.L.K.E.R.: Oblivion Lost, is a post-apocalyptic first-person shooter video game by Ukrainian developer GSC Game World.

The game uses a software feature called the "X-Ray engine". It features an alternate reality theme, where the second nuclear disaster happens at the Chernobyl Nuclear Power Plant in the near future and makes strange changes happen to the area around it, which create a lot of mutated animals, plants, and change the laws of Physics. The game has a storyline that lets the player have a lot of freedom, and features gameplay features such as trading and two-way communication with NPCs. The game includes features of role-playing and economic games.

Some phrases used in the game ("The Zone", "Stalker") as well as the idea of the game, are borrowed from the popular science fiction book Roadside Picnic by Boris and Arkady Strugatsky and the 1979 film Stalker, based on the book.
GSC Game World talked about the game's AI in January 2005. IGN said that the game, while similar to Far Cry, will have more wildlife, and that the way animals act in the game is as important to them as the humans. The animals anger will vary with how hungry and tired they are, as well as other things. So, the game will have some idea of fight or flight to it.

Gameplay 
In the game, the player is known as "The Marked One" who is a Stalker, a person who lives in the Zone and makes a living collecting "Artifacts" and selling them. The Zone has a lot of danger in it.
The type of game is a mix of a RPG and a FPS, though the player does not get attributes like Strength of Constitution, or get more powerful, which is different from a normal computer RPG. The role-playing part is mainly about normal RPG elements, such as storyline and the way other people in the game act with the player. But, the game does not let the player have a lot of choice when it comes to talking to characters in the game. Unlike RPGs such as Knights of the Old Republic, the number of different conversations the player can have with NPCs in the game is quite small and does not change the way that the game will end for the player a lot.
Bullet physics 
S.T.A.L.K.E.R. uses "realistic" bullet physics, that is, the way that the bullets move is like how a bullet would move in real life. The bullet physics are similar to tactical shooters such as Ghost Recon Advanced Warfighter or Call of Duty 2. Bullets are affected by gravity, and weapons are highly inaccurate when fired "from the hip". To be sure of hitting the enemy at long range, players must aim using the iron sights on their guns. Also, bullets do "realistic" damage, and the player can die after only being shot a few times (but to make up for this, later in the game the player can get different armor suits that increase the amount the player can be shot before dying).
Artifacts 
"Artifacts" are the product of 'anomalies', which occur randomly throughout the game. Anomalies are normally a few metres across, these areas are dangerous to enter and can instantly kill the player or cause serious injury. They can be seen by looking for swirling leaves, heat waves, wind moving about, and electricity. An anomaly will be in the game for about one week in game time, and once they have disappeared the player is able to collect the artifacts left behind, which can be traded for supplies, or worn to enhance some player abilities, with normally some bad side effects; for example, there is an artifact in the game that can make bullets less likely to hit the player, but will slowly give the player radiation sickness, which will eventually kill the character being played.
Mutants 
The local animals and plants were altered a lot by the years of radiation. They have become more dangerous, and have developed natural defenses to survive the harsh world. There are also a lot of people that were mutated by the radiation from the second explosion in the power plant.

Human factions 
The stalkers find it difficult to hunt for artifacts because the Ukrainian Military is in the area, trying to stop the zone getting bigger, and help control the mutant. The Military is an enemy of anyone who is not Military, and will work as a big team to attack anyone they see using heavy force and the use of Mi-35 Hind gunships, which are attack helicopters.
The player also works with other NPCs in the Zone, and can help Stalker factions and receive missions, which further the storyline. Players are able to explore over 30 square km of the Zone, including the ghost town of Pripyat and the empty Chernobyl Nuclear Plant, while meeting animals and plants mutated by radiation as well as other Stalkers and NPCs.

Technical features

Artificial intelligence 
The game uses uses GSC Gameworld's proprietary ALife artificial intelligence engine. ALife supports more than one thousand characters living in the Zone.
The NPCs act as if they really are alive, having different states, such as task accomplishment, combat, rest, feeding and sleep. The monsters in the game also act in this way. These monsters will move in large groups. The non-scripted way the characters work means that there are an unlimited number of random quests. For example, rescuing Stalkers from danger, killing Stalker renegades, protecting or attacking Stalker camps or searching for treasure. The AI characters travel around the entire zone as they want.

Numerous different ways of playing the game can be used, such as using stealth and sniping. The NPCs will react in a different way to each of them.

Weather 
A weather system works in various parts of the landscape and let the weather act as if it is real, letting the game have weather such as sunshine, storms and showers. The weapons available, the way the AI acts, game tactics and ranking systems will depend on the weather.
Multiplayer 
Multiplayer, like many other new games, will work over both LAN and the Internet with up to 32 players. Currently the three game modes are Deathmatch, Team Deathmatch and Artifact hunt. The game will also use a ranking system.

Initial concept 
Early in the development of the game it was named Oblivion Lost, and the game was planned to have more of a futuristic theme before the idea was reworked to set the game in Chernobyl, being a nearby location to the game's Kiev based development team. Eventually, this was reflected in the change of the game's subtitle to Shadow of Chernobyl. Screenshots and trailers of this early version can be found on various web sites, depicting the robots and spacecraft originally planned for the game.
While the source of the Zone may still turn out to have extraterrestrial connections (like in Roadside Picnic, where the Zone is thought to have been an absent-minded, accidental creation of a careless, vastly superior alien race), there is no indication that such more direct manifestations will return.

Development delay 
The game was first announced in November 2001 and has had its release date, originally in 2003, pushed back several times. Meanwhile, hundreds of screenshots of the game have been released, as well as dozen preview video clips, accompanied by other forms of promotion by GSC, such as inviting fans to their offices in Kiev to play the current build of the game. However, due to the delays some considered S.T.A.L.K.E.R. to be vaporware, like the game Duke Nukem Forever, or fear that the game may become a new Daikatana.
In their E3 Awards for 2005, IGN gave S.T.A.L.K.E.R.'s absence the award of "Biggest PC Surprise"; the runners-up were the absence of Fallout 3 from the show, and the lack of a new announcement from Blizzard Entertainment.

In February 2005, THQ expressed desire to see the game released toward the end of its 2006 fiscal year (March 31 2006) but maintained that no release date had been set. In October, 2005, THQ confirmed that S.T.A.L.K.E.R. will not be out "until the second half of THQ's 2007 fiscal year - October 2006 at the earliest." In February 2006, THQ revised this possible release window, saying the game would not be in stores until the first quarter of 2007.

In an interview at the Russian Gameland Awards, PR Manager Oleg Yavorsky indicated that release was planned for September 2006.

In 2006, the game came 9th in Wired'''s Vaporware '06 award.
THQ ran a competition in January 2007 offering the lucky winners the chance to play the beta version of S.T.A.L.K.E.R, in a 24-hour marathon session. The event, scheduled to take place on the January 24 2007, was subsequently changed to a 12-hour session days before it was supposed to occur.

On the morning of the event, the 'lucky' winners were met at the venue by the THQ staff that had organized the event, who were embarrassed to report that they had been unable to get any copies of the game. In late February GSC managed to release a public beta. Multiplayer demo was released to public on March 15 2007.

On March 2 2007, it was announced that the game had gone gold.
Reception 
So far, publications which have reviewed the title have been largely positive, noting the immersive, atmospheric setting and open-ended, rewarding gameplay. Some aspects of the game, such as the translation of printed text, the absence of subtitles for spoken Russian, and general game performance, have received negative criticism. It has also been noted that there are numerous sporadic bugs which can affect gameplay, although most of these are considered minor. However, in the newly released patch 1.0001 it is claimed that many bugs and glitches were fixed. Another common criticism is the fact that less than half of the map is actually accessible by the player.

Publications which have submitted reviews include IGN U.S. (8.2/10), IGN Australia (8.9/10), GameSpot (8.5/10), Australian PC User 95% and PC Gamer'' (87%). Ukraine's own Gameplay magazine awarded it 4.5 out of 5. UK based website Mansized  scored the game 4/5.
Plot 
Several years after the Chernobyl disaster, the Zone was occupied and "repurposed" by several research projects run by the Soviet government. Facilities were constructed or expanded under the abandoned military bases and civilian factories and industrial sites in the area, and a large lab was established directly beneath Reactor 4 and its Sarcophagus. These experiments were focused primarily on various aspects of the mind, including creating and enhancing ESP in humans, psychotronic weapons, and an experiment intended to create a human hive mind: the "Collective Consciousness," or "C-Consciousness," project.
This distortion of the noosphere powered by C-Consciousness and the machinery it was connected to created the anomalies and many of the mutants that inhabit the Zone in 2012. Desperate to correct its mistake and in order to shield itself from outside interference, especially the meddlesome "Stalkers" beginning to appear in the Zone, the C-Consciousness created an "Alien Monolith" in the center of the gutted Reactor 4, and used its ability to affect the minds of normal humans to create the "Monolith" cult, a group of heavily armed zealots whose tenets included worship of the Monolith and the prevention of "heretics" from approaching the remains of Chernobyl. They converted the Steel Yard radar facility near Pripyat into a powerful "Brain Scorcher" that would blast the mind of any unprotected human who approached too close, turning them into mindlessly aggressive zombies (while allowing C-Consciousness to select some individuals to brainwash into new members of Monolith)
. Finally, they used some of their agents (former Stalkers spread throughout the Zone) to disseminate stories of a "Wish Granter" at the heart of Chernobyl, ensuring that anyone who did manage to evade both the Monolith faction and the Brain Scorcher would be drawn to the Monolith and disposed of, rather than discovering the existence of the C-Consciousness lab.
This lasted for several years, but the continued efforts of C-Consciousness were unable to repair the damage they had done to the Zone. In fact, the damage appeared to be getting worse, with "Blowouts" deepening the distortion of the noosphere around the Zone at irregular intervals. Still, the C-Consciousness entity persisted in its experiments, behind the shields of the Monolith and the Wish Granter myth, the Monolith faction's patrols, the Brain Scorcher, and the dangers of the Zone itself. Occasionally, though, special circumstances would require an agent, a human able to do what was needed to preserve the Zone's secrets without revealing the existence of the C-Consciousness project. In these cases, Stalkers who were tough and resourceful enough to make it to or past the Brain Scorcher would be captured, brainwashed, and sent back into the outer areas of the zone on one of the "Death Trucks." These agents were marked with the tattoo "S.T.A.L.K.E.R
.T.A.L.K.E.R." This is where Strelok, the main character, enters the story.
Strelok and his allies, Ghost, Fang, and Doc, were a group of Stalkers who had a particular interest in what exactly lay at the center of The Zone. At some point a few weeks before the start of the game, they managed to slip past the Brain Scorcher and all the way to the Nuclear Power Plant, finding the Monolith, an electronically locked vault door beneath the Monolith chamber (which leads to C-Consciousness), and documents hinting at the fact that the giant glowing Monolith was in fact a deliberate trap for anyone attempting to discover the secrets of the Zone. Unfortunately, they were forced to retreat, and their next attempt to penetrate into the heart of the Zone met with disaster. They had managed to obtain an electronic lockpick that would open the vault door, but this time the Monolith was ready for them and they were forced to retreat again, and their escape was further complicated by a blowout. Strelok was caught in the blowout and rendered unconscious with a severe case of amnesia
. This made for a perfect subject for the conditioning process for a human agent of the C-Consciousness entity. Ghost and Fang escaped, but Fang was seriously wounded and died before the pair made it out of Pripyat, with Ghost moving on to find "safer" work in the outer regions of the Zone.
By this point, Strelok had become a serious threat to the security and secrecy of the C-Consciousness lab and the entity contained there, and it was decided that Strelok must be killed. However, due to unknown factors, C-Consciousness made a mistake: not realizing the identity of the man who had been caught in the blowout, they attempted to program him to kill Strelok, when in fact the man was Strelok. A second accident, the chance destruction of the Death Truck meant to carry this new agent back to the outer Zone, resulted in a loss of C-Consciousness control over him. Strelok was a free agent once again, though confused, amnesiac, and stripped of his possessions. The mission to kill himself led Strelok to retrace his steps through the past few weeks, tracking down his old associates and, over time, putting back together the evidence that had led him to become a danger to C-Consciousness in the first place
. With the help of Doc to reveal his identity and to point him in the direction of a backup cache of documentation and another electronic lock pick, Strelok returned to Chernobyl and penetrated to the chamber under the "Monolith," destroying the projection device that created the illusion.
C-Consciousness, having no other option, confronted him to offer an explanation of their actions, the nature of the Zone, and a choice: to join them, bolster their numbers, help them repair the harm they had caused and shepherd humanity's consciousness towards peace, or to face a final confrontation with the remaining forces of the Monolith Faction in an attempt to reach the heart of the real C-Consciousness Lab, in order to put a stop to their manipulations and machinations.

References

Other websites 

 Official website
 THQ's Official S.T.A.L.K.E.R website
 GSC Game World's Official website

Windows games
THQ games
2007 video games
Shooter video games
Horror video games
List of bridges in the United States is a work in progress.

Bayonne Bridge, joins New York and New Jersey
Brooklyn Bridge, in New York City
Clark Bridge, joins Illinois and Missouri
Goethals Bridge, joins New York and New Jersey
Golden Gate Bridge, in San Francisco, California
Manhattan Bridge, in New York City
Bataan-Corregidor Memorial Bridge, in Chicago, Illinois
Mackinac Bridge, in Michigan
Outerbridge Crossing, joins New York and New Jersey
Queensboro Bridge, in New York City
Rainbow Bridge, joins New York and Ontario, Canada
Thousand Islands Bridge, joins New York and Ontario, Canada
George Washington Bridge, joins New York and New Jersey
Williamsburg Bridge, in New York City
Zilwaukee Bridge, in Michigan

Related pages
 List of bridges

United States-related lists
United States
Osborne's bull was created as an advertisement for a sherry in 1956. Many people see it as the unofficial image of Spain. The bull is seen in semi-profile. The bulls used today are about 14 metres high, and are made out of about 70 plates of iron. There are many people who think it as a god.

Symbols
Desalination means any process that removes the excess salt and other minerals from water in order to obtain fresh water suitable for animal consumption or irrigation. Most desalination is by distillation. Some is by reverse osmosis or other methods.

The main purpose is to make water for people to use. The salt is usually carried away as brine but in some places the solid salt is extracted. 

Desalination  of brackish water is done in the United States in order to meet treaty obligations for river water entering Mexico. Several Middle Eastern countries have energy reserves so great that they use desalinated water for agriculture. Saudi Arabia's desalination plants account for about 24% of total world capacity. The world's largest desalination plant is the Jebel Ali Desalination Plant (Phase 2) in UAE. It uses multi-stage flash distillation, dual-purpose and it is capable of producing 300 million cubic meters of water per year.
Methods
Distillation 
Multi-stage flash (MSF)
Multiple-effect (MED|ME)
Vapor compression (VC)
Evaporation/condensation
Membrane processes
Electrodialysis reversal (EDR)
Reverse osmosis (RO)
Nanofiltration (NF)
Forward osmosis (FO)
Membrane distillation (MD)
Cold (freezing)
thermal
Solar humidification 
Methane hydrate crystallisation
High grade water recycling

The traditional process used in these operations is vacuum distillation — essentially the boiling of water at less than atmospheric pressure, and thus a much lower temperature than normal. Due to the reduced temperature, energy is saved.

References
Other websites 
 Middle East Desalination Research Centre 
 Encyclopedia of Desalination and water and Water Resources
 Global Water Intelligence - monthly newsletter featuring 'Desal Project Tracker'
 Water Desalination Report - weekly newsletter on international desal 
 International Desalination Association
 Desalination & Water Reuse - Official magazine of the International Desalination Association 
 European Desalination Society
 IAEA - Nuclear Desalination 
 German Desalination Society - DME
 Geothermal Desalination 
 SDSU (San Diego State University) Center for Information Technology and Infrastructure (CITI) International Consortium of Advanced Technologies and Security 
 "Desalination Journal" and Desalination Directory of the European Desalination Society
Desalination by humidification and dehumidification of air: state of the art 
 Zonnewater - optimized solar thermal desalination (distillation)
 SOLAR TOWER Project - Clean Electricity Generation for Desalination.
Solar Desalination using the MEH-Method
 Article: Water issues prompt new look at desalination 
 Desalination bibliography Library of Congress
 Water-Technology
Water Desalination Worldewide, Market, Technologies and Companies
Cheap Drinking Water from the Ocean - Carbon nanotube-based membranes will dramatically cut the cost of desalination
BBC2 Newsnight Film: Israel build the world's largest desalination plant 
Solar thermal-driven desalination plants based on membrane distillation 
Encyclopedia of Water Sciences, Engineering and Technology Resources
Solar energy is a type of energy that comes from the sun's heat. People have been using solar energy for thousands of years in different ways, such as heating, cooking, and drying. Nowadays, it is also used to create electricity in areas where other sources of power are not available, such as remote locations and even outer space.

The cost of generating electricity from solar energy is decreasing, making it a more affordable option. Since the sun provides heat and light constantly, solar energy is considered a renewable energy source and an alternative to non-renewable resources like coal and oil.

Energy uses
Solar energy is used in various ways today, including:
 As a source of heat for making hot water, heating buildings and cooking
 To generate electricity through the use of solar cells or heat engines
 To take the salt away from sea water, making it drinkable.
 To use sun rays for drying clothes and towels.
It is used by plants for the process of photosynthesis.
 To use in cooking (Solar cookers).
Energy from the Sun 
After passing through the Earth's atmosphere, most of the Sun's energy is in the form of visible light and infrared light radiation. Plants convert the energy in sunlight into chemical energy (sugars and starches) through the process of photosynthesis. Humans regularly use this store of energy in various ways, as when they burn wood off fossil fuels, or when simply eating plants, fish and animals.

Solar radiation reaches the Earth's upper atmosphere with the power of 1366 watts per square meter (W/m2). Since the Earth is round, the surface nearer its poles is angled away from the Sun and receives much less solar energy than the surface nearer the equator.
At present, solar cell panels convert, at best, about 15% of the sunlight hitting them into electricity. 
The dark disks in the third diagram on the right are imaginary examples of the amount of land that, if covered with 8% efficient solar panels, would produce slightly more energy in the form of electricity than the world needed in 2003.

Types of technologies 

Many technologies have been developed to make use of solar radiation.  Some of these technologies make direct use of the solar energy (e.g. to provide light, heat, etc.), while others produce electricity.

Solar power plants 
Solar power plants convert sunlight into electricity, either directly using photovoltaics (PV), or indirectly using concentrated solar power (CSP). Concentrated solar power systems use lenses or mirrors and tracking systems to focus a large area of sunlight into a small beam. Photovoltaics converts light into electric current using the photoelectric effect.

Photovoltaics

Concentrated solar thermal

Rank

Solar cooker
Solar cooker 

Solar cooking uses the Sun as the source of energy instead of standard cooking fuels such as charcoal, coal or gas.  Solar cookers are an inexpensive and environmentally sound alternative to traditional ovens. They are becoming widely used in areas of the developing world where deforestation is an issue, financial resources to purchase fuel are limited, and where open flames would pose a serious risk to people and the environment. Solar cookers are covered with a glass plate. They achieve a higher temperature by using mirrors to focus the rays of the sun.

Solar heater  
 The Sun may be used to heat water instead of electricity or gas. There are two basic types of active solar heating systems based on the type of fluid — either liquid or air — that is heated in the solar energy collectors. (The collector is the device in which a fluid is heated by the Sun.)
Liquid-based systems heat water or an antifreeze solution in a "hydronic" collector, whereas air-based systems heat air in an "air collector."  Both air and liquid systems can supplement forced air systems.

Solar cells 

Solar cells can be used to generate electricity from sunlight. It is a device that converts light energy into electrical energy. Sometimes the term solar cell is reserved for devices intended specifically to capture energy from sunlight, while the term photovoltaic cell is used when the light source is unspecified.
Solar cells have many applications. They have long been used in situations where electrical power from the grid is unavailable, such as in remote area power systems, Earth-orbiting satellites and space probes, consumer systems, e.g. handheld calculators or wrist watches, remote radiotelephones and water pumping applications. A large no. of solar cells are combined in an arrangement called solar cell panel that can deliver enough electricity for practical use. Electricity produced by solar panels can be stored in rechargeable solar batteries, which is then drawn upon when required.

Related pages
 List of renewable energy topics

References
References

Other websites 
 Solar Energy Industries Association is the national trade association for the US solar energy industry and has information on current commercial technologies and market developments.
 Direct solar U.S. Department of Energy: Energy Efficiency and Renewable Energy - Thermal water splitting
 U.S. Department of Energy: Energy Efficiency and Renewable Energy Solar History Timeline
 National Renewable Energy Laboratory: Concentrating Solar Power (CSP)
 Solar energy in the News 
 ESTIF - European Solar Thermal Industry organization (statistics, market situation)
 Solar perspectives in Italy  - Information on the Italian Solar Market
 Online article by scientist Jonathan G. Dorn, July 22-2008  The solar thermal power industry experienced a surge in 2007, with 100 megawatts of new capacity worldwide.