Mechanisms that wrap around, secret armchairs, unsolved mysteries of paintings - the axis of the list of what the coolest engineer and artist of the Renaissance era has left behind.
On the day of the birth of Leonardo da Vinci, we have collected for you a collection of the most famous works and mysteries of a genius, who had anticipated his hour.
Prototype cullet
Leonardo actively advertised his military-technical ideas. One of them revealed the essence of the cullet. Vіn not a moment swidko vypuskat kuli from one trunk. Ale zate instantly saw volleys through short intervals, and yakbi buv budovaniya, effectively mowed down the infantry, scho comes.
car
It is believed that the idea of creating a car originated with Leonardo in the distant 1478. But only in 1752, a Russian self-taught mechanic, a villager Leonty Shamshurenkov, managed to pick up a “self-made carriage”, which was driven by the power of two people.
The first bicycle in history
The first technical bicycle seat belongs to Leonardo da Vinci. The Meiningen Chronicle of 1447 tells the fate of attachments, that they move, that they are driven into the waters.
Bearing
First, the idea, like a rich one, was born in the hours of the Roman Empire, but historians affirm that the first strokes of the bearing appeared in the letters of Vinci themselves.
Parachute
In his manuscripts, Leonardo described the exact dimensions of the outhouse for a carefree descent from the great heights. Swiss Olіv'є Tepp virіshiv yogo on the road and strebnuv from a height of 650 meters with a parachute. Behind the words of the viprobuvach, the streak was safe, but such a parachute is practically not cured.
scuba and lizhi
Leonardo loved the water: he explained the instructions for zanurennya, wines and described the deep dive apparatus for underwater swimming.
Tank
Such an axle basin on wheels with garmats and vezhey and є great-grandfather of modern tanks. Vіn buv equipping with a system of gear wheels, which folded the sequence. Vіsіm people were thieved during the battle by the outer shell, they could deliver such a “їzhak” on their own right into the thick of the battle without being injured.
Ratchet hoist
Leonardo vigadav impersonal dribnits, yakі bule more curly. Let's sweat them out by stopping at their own mechanisms. The ratchet is a blocking attachment, which does not allow the shaft to wrap around the gate directly.
Attachment for winding thread on a spool
In his own time, Leonardo asked the life of a rich kravtsy.
Robot Face
It is important that in 1495 Leonardo da Vinci first formulated the idea of a “mechanical person”, otherwise seemingly a robot. According to the master’s idea, his attachment was a mannequin, clothes were worn by the face of the owner and the building was made to create a sprinkling of human ruins.
Over the solution of the mystery of Mona Lisa's laughter, the successors are already richly fateful. Chi does not perebuvay vcheniya, which reminds: "The secret has been revealed!" Deyakі vvazhayut, scho raznyattya virazu denunciation of Giocondi to lie in the form of special psychic skin qualities. Komus out
let's sum it up, think about someone, cunning someone, anger someone. And dehto vvazha, scho Gioconda zovsіm navit and do not laugh!
Manuscripts
Leonardo da Vinci could write both with his hands, moreover, in a "mirror-like" way - that is right-handed in plain, if you want to, for example, for listing with officials, victorious in the original style of the sheet. Naytsіkavіshe, scho vinakhіdnik specially pardoned at the armchairs, schob zapobіgti, seeming today's mine, promissory spying. The axis of this rich mystery of genius is left unrevealed for the people.
human anatomy
The fact that Vinci considers a caricature little baby as a wine-maker is a reminder of the fact that Vinci often portrays the death of human bodies. In September 2005, the successors revealed the secret laboratory of Leonardo. There, unoccupied frescoes of the master were found, as well as a room for the dissection of corpses (Leonardo and yoga scientists uncovered hundreds of the dead, studying the anatomy).
"Mystery Supper"
Creating a fresco "The Last Supper" by Leonardo da Vinci for a long time already shukav idealni model. Jesus can inculcate Good, and Yuda, who has won yoga at my meal, is Evil.
Leonardo richly interrupted the work, defying the jokes of naturalists. Once, listening to the church choir, having strummed in one of the youthful consonances the image of Christ and having asked for yoga in his master, having scribbled a sprat. It's been three years. "The Last Supper" may be completed, Prote Leonardo still did not know a suitable sitter for Yuda. The cardinal, who vindicated the cathedral for painting, quarreled the artist. The first axis after long-term poshukіv the artist patted the people who were lying in the sewage ditch - young, but before the hour decrepit and drunk. The artist ordered his commemorators to deliver yoga to the cathedral. The person didn’t understand well what it was like, and it’s out of place to know, and Leonardo, having depicted on the canvas the appearance of a person, that she was mired in sins. If you have finished the work, the zhebrak, which at that time has already come to you, has already come to you, has gone to the canvas and woofed:
- I already finished this picture earlier!
- When? - Zdivuvavsya that Vinci.
- Three fates to that, even before I have spent everything. At that hour, when I was sleeping at the choir, my life was like a dream, like an artist who wrote from me Christ.
Not long ago, the little sketches of Leonardo da Vinci for the mechanical face began to appear.
The robot is the face of a moment to sit, wrap your arms, shatter your head, twist and curl the slit.
The robot was designed with an eye on the possibility of trimming in the hands. It is not enough with the robotic hands to work the mechanical programming of attachments at the breasts. The legs were guilty of twirling behind the help of the handle, to bring the cable from the hands, tying the legs.
After 36 years after the creation of sketches, the idea of the mechanism of the robot-litsar was vikoristan as the basis for the self-tapping mechanical lion, which was created behind the Medici towers. When Francis1 entered the throne in front of him, the king of France, there was a lion, a snake that destroys its own mission. Michelangelo Buanorotti in the booklet, seen in Florence in 1600 people, also made the automatic machine - a mechanical left, like a proishov kilka krokiv. Unfortunately, Leonardo da Vinci's robot lion didn't survive.
Qi automatic machines were the fronts of mobile robots.
You know you?
Shield of the Gorgon Medusa
As if a well-known villager asked Father Leonardo to know the artist, so that he would paint a round wooden shield. Sir P'ero gave a shield to his son. Leonardo depicted the head of the gorgon Medusa, and that the image of the monster celebrated on the look-out in a well-worn way, victorious as the nature of lizards, snakes, horses, caterpillars, bats and other creatures from faceless ones, like a terrible miracle, , like it was tearing off with its breath and it was blowing up again. ”
The result turned over yoga ochіkuvannya: if Leonardo showed the finished work of the father, that zlyakavsya. Sin, saying to you: “Ty tvir serve that, for the sake of which the wines are broken. So take it and give it yoga, because it’s so good, like you’ll see the works of art.” Sir P'ero did not see the robot of Leonardo the villagers: having taken away another shield, purchases from the old. Father Leonardo sold the shield of Medusa at Florence, having won for a hundred ducats. Behind orders, the whole shield of transitions to this Medici, and if the wines were ruined, the sovereign rulers of Florence were driven out of the city by the people.
* Gorgons in ancient Greek mythology - the snake hair of a monster, the daughter of a sea deity. One of them, the Gorgon Medusa, could bewitch people with a look, Medusa's look turned life into a stone.
Burial of Leonardo
In the midst of Leonardo's slaughter, they inspired cooking and the art of serving. At Milan, for 13 years, he was the order of court banquets. Vіn vinayshov sprat of culinary outbuildings, which made it easier for the cooks. The original grass “view of Leonardo” – thinly sliced stewed meat, with vegetables laid to the beast – was highly popular on court banquettes.
Leonardo's handwriting
Leonardo, however, was kindly led with his right and left hands. To say navit, scho vin instant at once write different texts with different hands. Prote bolshіst prats vіn having written with the left hand right-handedly. Deyakі vvazhayut, yogo mirror handwriting bv іndivіdualnou osoblivіstyu Leonardo, tobto. it was easier for you to write like this, in a normal rank.
Top 10 wines of Leonardo da Vinci
Leonardo da Vinci is a great Italian artist (painter, sculptor, architect) and scholars (anatomist, mathematician, physicist, naturalist), a true representative of the “universal human being” type.
1
The famous little ones, which are accompanied by explanatory inscriptions, the victors of Leonardo da Vinci, about 1490 years and placements in one of the magazines. On the new one, the figure of a naked man is depicted in two overlays, one on one position: with arms extended to the sides and legs, inscribed in the colo; with extended arms and extended legs, inscribed in a square. Babies and explanations of something new are sometimes called canonical proportions.
2
The only yoga wine, which has taken away the recognition for yoga life, is a wheel lock for a pistol (winding with a key). There were few extensions on the cob of the wheeled pistol, but even until the middle of the 16th century, popularity among the nobles
3
Leonardo learned that he introduced a new pictorial technique. The new line has the right to rozmitist, more so її bachimo. Vіn svіdomiv povіdomiv rozsіyuvannya svіtla in poіtrі vynіknennya sfumato - serpanka mіzh staring that izobrazhenim subject, scho pom'yakshuє kolіrnі contrasts і іnії. As a result, realism in painting has changed to a brand new slab.
4
“I am robitim of the closed chariots, like they are safe, and it is impossible to attack them; a car, which is not afraid of the attack of a great number of enemies with the destruction of one of the frets and one of the artillery. Predudov Kolisnitsi, guilty of Sliduvati Pіkhotsі, without the non -rejection of Skodi abed pereshoda ”I, Leonardo Siyannya Panіki, Tu Ruinwannya Pereonyv Bula Bul was in the yogo project, the form of auto mmoblya turtle, with the ukriphini plastes, with the intra -thyroid plastes, with the intravyeu, with the intravye, The car is operated by 8 people to drive the wheels.
This type of bridges, the inventions of Leonardo da Vinci, could be redeemed for the Viysk people of that hour. The place, which is formed from one span, was fastened to the shore with a vertical hinge, which allowed it to wrap around. The advantage of such an attachment is the efficiency of the throat.
6
The car from the tree behind Leonardo's armchairs sounded like 2004 rock. The events of one of the museums in Italy inspired the idea of a genius into life, to a great surprise, by working the mechanism exactly as if letting Da Vinci go.
7
From the little pictures of Leonardo da Vinci, it is clear that the statement about the neutral plane of the viniclo in the new and the best of the crossbow. The butt of the little ones of a gigantic catapult for shooting stones. The bending of the arc of the chain was carried out behind the additional twine sconces; the stone has come out of the intestine, roztashovanoy in the center of the double pull. Like a thief, so is the turd for the stone painted (on a larger scale) such as on the little ones of a crossbow.
8
Leonardo's robot is a human-like mechanism, the technology of which was developed by Leonardo da Vinci around 1495. The robot armchair was found in Leonardo's papers from the 1950s. It is not clear why the distribution was made. On the frame of the robot, German-Italian face armor was put on; The technology was often grounded on the achievements of Leonardo in anatomy, the foundation of Vitruvian people.
9
Leonardo da Vinci chimed in with the problems of the field. At Milani wines, they robbed a lot of little ones and vyvchav litalny mechanism of birds of various porods and kazhanivs. Having seen the Crimean guardian of the wines, and after seeing them, the stench was not far off. Leonardo would like to induce a lethal apparatus. Win kaz: He who knows everything, he can do everything. Aby only recognize - and there will be wings! On the back of Leonardo's head, having solved the problem of help for help, kril, who collapse with the muck force of people: the idea of the simplest apparatus of Daedalus and Icarus. Ale potim vin diyshov thoughts about the life of such an apparatus, to which a person is not guilty of being attached, but is guilty of saving new freedom, to cherub it; bring your apparatus into ruin, guilty of your own power. Tse, in essence, the idea of an airplane. In order to successfully and practically induce that victorious apparatus, Leonardo did not stick out more than one thing: the idea of a motor that can have enough strength. Until you decide wines. Leonardo da Vinci worked on the vertical plane and landing over the apparatus. Ninish vcheni authoritatively assert that this construction cannot be let out. However, all wines of Leonardo dosi are filled with one of the most important ones. The construction is guilty of collapsing by the physical strength of some people.
10
The original design of the parachute was da Vinci's cross in his notebook in 1483 and was accompanied by a note about the safety of a person's haircut, no matter how tall, with such an addition. Vinahid Leonardo da Vinci having taken away the practical confirmation in 500 years after having made the first line of the world's parachute like a wine. The Briton Adrian Nicholas, having cut from the winding coulis from a height of 3000 meters above the ground, ignoring the admission of experts about those who are cunningly attached to the sailcloth, that tree is not lethal. Nicholas landed successfully on the vast open territory of Mpumalanga in Pivdenniy Africa, rozpovidayuchi that watering bv m'yakshim, lower for the help of modern parachutes. And more hostile. Eyewitnesses were enchanted by yoga beauty. Prote zakhoplennya was replaced by fear: no one knew, singsong, what to land Adrian, what to step on the ground.
The government of Ecuador let Julian Assange sit in the London embassy. The founder of WikiLeaks was hounded by the British police, and they were already called the greatest evil in the history of Ecuador. Why take revenge on Assange and what is on the new check?
Julian Assange, a programmer and journalist from Australia, gained wide popularity after he founded the WikiLeaks website in 2010 by publishing secret documents to the US Department of State, as well as materials from other military events in Iraq and Afghanistan.
Ale to find out about those whom the policemen, pіdtrimuyuchi pіd hands, brought out of life, it was hard to finish. Assange let go of his beard and did not look like an energetic person, having put it in photographs.
Behind the words of the Ecuadorian President Lenin Moreno, Assange was forced into the back room through his repeated violation of international conventions.
It should be clear that in the police station in the center of London there will be a dock, the docks will not stand at the Westminster magistrate's court.
Why the president of Ecuador is ringing in the air
The largest president of Ecuador, Rafael Correa, called the decision of the ninth order the greatest blessing in the history of the country. "Those who vin (Moreno. - Approx. ed.) robbed - tse evils, which people will never forget," Correa said.
London, navpaki, yakking Moreno. The British MZS vvazhayut that justice won. The representative of the Russian diplomatic department, Maria Zakharova, has another thought. "The hand of "democracy" is squeezing the throat of freedom," she said. At the Kremlin, they hung hope that the rights of the arrested person would be extended.
Ecuador lied to Assange, to which the president did not stop looking at the centre-left, criticizing the US policy and instilling the WikiLeaks publication of secret documents about the wars in Iraq and Afghanistan. Even before that, as Internet activists needed a seat, I got to know Correa especially: I interviewed him for the Russia Today channel.
Prote in 2017, the power in Ecuador changed, the country headed towards the United States. The new president, calling Assange "stones at the cherevik" and once giving the understanding that the yogi rebuking on the territory of the embassy will not drag on.
In Correa's thought, the moment of truth has come, like the devil of a bygone fate, if US Vice President Michael Pence arrives on a visit to Ecuador. Then they all screwed up. “You can be sure: Lenin is just a hypocrite. Vin has already talked with the Americans about Assange’s share. And now they’re trying to do it in such a way that they knocked us out, it seems that Ecuador is continuing the dialogue in no way,” Correa said in an interview with the Russia Today channel.
Yak Assange making new enemies
The day before the arrest, the editor-in-chief of WikiLeaks, Kristin Hrafnsson, said that Assange was under total scrutiny. "WikiLeaks has revealed a large-scale spy operation against Julian Assange in the embassy of Ecuador," citing the vin. For yoga tribute, cameras and dictaphones were set up around Assange, and the removal of the video was transmitted to the administration of Donald Trump.
Hrafnsson specified that Assange was picked up from the embassy earlier this year. What hasn't happened to the fact that WikiLeaks has publicized this information. About the plans of the ruler of Ecuador, the portal was told by a high-ranking dzherelo, the prote head of the Ecuadorian MZS Jose Valencia, speaking a little.
Vidvorennia Assange blowing up the corruption scandal around Moreno. With the fierce WikiLeaks, having published a package of papers INA Papers, the operations of the offshore company INA Investment were chilled, as if the brother of the Ecuadorian leader had fallen asleep. Quito was told that Assange and Venezuelan President Nicolas Maduro and the head of Ecuador, Rafael Correa, would overthrow Moreno.
On the cob of the day, Moreno was shy about Assange's behavior at the London mission of Ecuador. "We are responsible for defending the life of Pan Assange, but we have already crossed all the cordonies in the sense of destruction, please, to what extent they have come with him," the President said. . ". In the meantime, in the fierce past fate, it became known that Assange at the embassy was given the opportunity to interact with the outside world, zocrema, and he was given access to the Internet.
Why Sweden blamed Assange's retrial
For example, the last fate of the death of ZMI s sent to the dzherel was reminded that Assange should be called to the United States. It was not officially confirmed, however, through the position of Washington, Assange had a chance to hide in the Ecuadorian embassy six years ago.
Sweden, at the beginning of 2017, pinned down the investigation of two certificates about the grievance, in which they called the principal to the portal. Assange demanded, in the order of the krai, the compensation of the court's vitrates in the amount of 900,000 euros.
Earlier, in 2015, the Swedish prosecutor's office also took three calls through the end of the statute of limitations.
Where did the investigation lead to?
Assange arrives before Sweden in 2010, trying to fight back against American rule. Ale, having spent the first time at the right of the salary. At the fall of the leaves of 2010, a warrant for yogo arrest was seen near Stockholm, Assange was voted out at the international court. Yogo was hung up in London, the protégé let loose 240,000 pounds under the outpost.
In the fierce of 2011, a British court praised Assange's extravagance to Sweden, after which there were few successful appeals for the founder of WikiLeaks.
The British government placed him under house arrest in front of him, as a way to praise the decision about extradition to Sweden. Having destroyed the power of the obitsyanka, Assange, asking for a shelter in the embassy of Ecuador, as if he had been given. From that hour, the UK has its own claims to the founder of WikiLeaks.
What is now checking for Assange
As reported by the police, the person was re-arrested for a US request for extradition for publishing classified documents. At the same time, the intercessor of the head of the British MZS, Alan Duncan, said that Assange would not be sent to the Successful States, as he would be threatened with death penalty there.
The Great Britain Assange, better for everything, will stand before the court at the other half of the day on April 11th. Please check the WikiLeaks side of Twitter. Imovirno, the British government to achieve the maximum term of legalization in 12 months, helped the mother of a person to apply for a lawyer.
At the same time, the prosecutor's office of Sweden is looking into the possibility of updating the investigation for calls from the taxpayer. Lawyer Elizabeth Massy Fritz, yaka represented the interests of the victim, whom to achieve.
Most often, this is how Vinci thinks, if the language goes about painting, but in the middle of it, yoga robots will be wondrous wine walkers, one of them is a human-like robot.
Leonardo miraculously knowing mechanics, anatomy, the power of various materials. Often, the master created those that were not understood by his fellow students, and only after a hundred years they marveled, if they knew the yoga chair. The genius diligently ciphered his notes, which only added more problems to the successors, and some of the notes irrevocably arose. That's why a skin knowledge, a skin test of decoding, a skin model, as it was created, becomes a sensation.
Trochs about maister
The future artist, sculptor, architect, writer, scientist and engineer came to the world in 1452 near the Florentine town of Vinci.
Vіn buv illegitimate son of the notary P'єro ta selyanskoy ї vyvchiny. Vіn not mav prizvishcha: “yes Vіnchі” - adding to the name, it is transferred like “z Vinci” and pointing to the place of the people. Leonardo was trained by the artist Andrea del Verrocchio in Florence.
The Crimean humanities and art disciplines of winemaking chemistry, modelling, metallurgy, armchairs, manufacturing from plaster, shkiroy and metal. At 20 years, having entered the Guild of St. Luke, she took off the status of master. Already for hours of teaching, the talented master of the Volodymyr mastered the technique of painting better, lower mentor. So Vinci worked on the paintings, sculptures and frescoes, singling out the prayers of possible people.
At the same time, he twisted the life of the human body, opened the corpses and carefully painted the organs, the skeleton and the muck, often from a number of angles. Yogo pіdhіd zgodom began to be victorious when folding anatomical atlases. Leonardo, after spending time in the galleys of hydraulics and pneumatics, victorious driving force and power in order to bring cars to the road. Vіn rozroblyav vuzli and qіlі mehanіzmi, some of them were assigned to combat operations.
Nothing was given to the genius of something insignificant, to him to lay faceless wines in different spheres of life, in the form of cooking before sailing. Navit rozvagi greedy for the sights of the public, if you want to find it especially: the famous robot Leonardo da Vinci created for yourself for the sake of meti.
Acts of wine by Leonardo
So Vinci, having perfected the technique of painting, his paintings look richly realistic, lower than those of his predecessors. Vіn zrozumіv scho lightly rozsіyuєtsya in povіtrі mіzh the object that posterigach, after the contour of the objects exude clarity. Leonardo zmіg conveyed it in his paintings and denounced the appearance in theory. Priyom to wear the name "sfumato", in the translation of the Italian - "knowing how dim". Other artists quickly appreciated the new technique and adopted it.
Patience, interest in anatomy, as well as the birth of the work of the architect of that great Vitruvius, who is alive in the Roman Empire in the I century before ours, brought to the creation of the little Vitruvian people. This is an illustration of my comments, which explain the main mathematical proportions of the body. The engineering vision of Leonardo bore fruit.
Yogo wine-walkers ahead of the hour, stench still oppose awake, even models, like they will be behind armchairs of five years ago, miraculously work.
Models by Leonardo da Vinci
- A wooden vіzok, like it's on its own, collapses behind the help of springs, and a halmo is also transferred to the new one. Such a car of the Renaissance era was successfully launched on the cob of the XXI century.
- Da Vinci's parachute from the tree and the sailcloths softly landed on the test, which ripped off from the height of three thousand meters.
- The flying apparatus, which guesses the airplane, for the firmness of the fahivtsiv, cannot fly, wanting to be naive, for which the master tried to pick up the people at the front, shouting the honor.
- Vіysk rozrobki and Vіnchі are not less than cіkavі. The tank - the closed chariot against the enemy - is guilty of defending the infantry and the guard of the yakomog of the greater shkoda of the opponents. For the management of this unit, it is necessary to have a large number of people.
- Bridges, which can be easily endured and installed, singsongly, chirped the generals in that hour. The majestic catapult with a screwed commander is small for shooting stones.
Tsі pristroї so i was left on papers, and the share of the ring castle, which was actively victorious in the fire of the XV-XVII century, was revealed.
Since 1516, Leonardo is alive in France, having requested Francis I, and supervising the organization of court urochistas. For this, a part of the wine-growers will need a bula, in order to make the monarch more mature. Da Vinci had a miraculous ability to continue his work, to design mechanisms, to try them on the right, to demonstrate to the lookers and to take the city for work.
Vіn folded the outline of the inventory, with which he vikoristovuvav cipher and navmisno adding at the armchair zayvі elementi, imovіrno, schob іdeї not zmіg vikrasti and vtіlity in life htos іnshiy. The robot-face of Leonardo da Vinci did not become a culprit, but it was known about in the middle of the 20th century.
Armchairs from piece chairs people know in 1957 roci Carlo Pedretti. The records themselves were made in 1495 or 1496, but there are no reliable reports about those who could play Leonardo's robot in action. Mark Rosheim, an American robotics engineer, took up circuit design in 1996, and in 2002 achieved success and demonstrated an android, about which they forgot about five hundred years. The last contributor, Mario Thaddeus, having completed one more reconstruction, seemed to come closer to the original idea. Mekhanizm robitnik, all yogo details function as they should.
So Vіnchі knowing well, like the power of m'yazi, the sinew and the mud of the people, vin rozumіv the mechanics of the ruhіv living іstot. With the encouragement of Leonardo's work, all proportions were completed, as if they were following the Vitruvian people. Sob the android does not fall, its center of gravity is always guilty of rotting over the feet, and the shoulders, quilts and tassels are guilty of lying in the same plane. Woody loam, drotyan tendon, and a steel skeleton attached to the German-Italian crowns of the Middle Ages.
Robot face da Vinci
Mechanic virobnitstvo can turn your head, twist and close your mouth, collapse with your hands, sit and get up. The movements are even more plausible, and everything is the result of a robotic system of rollers and cables. At the android's breasts there is a strong attachment, a mechanical wine, where the principle of direct coding is victorious. The control of the upper and lower halves of the device is separate: you can control the knots in the tassels, knees and quilts using the help of the outer handle.
The robot-face of da Vinci building trim is somehow in the hands, it’s possible that yoga was designed for some kind of ceremony or a wedding. Sob for an hour the car was shifted without the participation of people, Leonardo instantly beat the water wheels or the crank mechanism. The principles of this model became the basis for further development - a mechanical left for Francis I.
Automatics, like foreseeing da Vinci, in the eyes of modern people look naive and awkward. And yet, the simplicity is ingenious, and the appearance of the latest analogues confirms that Leonardo is thinking in the right direction. Yoga practitioners draw inspiration from the XXIst century robotics. You want to create such a robot, and add electronics and the necessary programs. New embedding can change voices and computer commands. The old-fashioned android was understood and adopted, high to bring through hundreds of years.
7 scientific wines of Leonardo da Vinci