For which carbon dioxide is used. Methods for producing carbon dioxide
Dilution of forces, weakness, patient head, Depression is a familiar condition? Most often it happens in the fall and winter, and poor well-being is written off on a lack sunlight. But it's not about it, but in excessive content carbon dioxide In the air you breathe. The situation with the level of social premises and transport in our country is truly catastrophic. Duchot, increased humidity and mold are also a consequence of missing ventilation. Sealed plastic windows and air conditioners only exacerbate the situation. Do you know that with two-time exceeding (relative to the street background) of carbon dioxide in the air, brain activity is reduced by 2 times? By the way, it is the yawning students at lectures that are an indicator of high content of CO₂ in the audience. And very often the ventilation is absent in office buildings. What productivity can it be about, if a person simply does not work brains?
So, let's start with the basics. A person with breathing absorbs oxygen, and highlights carbon dioxide. Also, carbon dioxide is allocated when burning hydrocarbons. Average level On our planet in currently It is about 400 ppm (Parts Per Million - parts per million, or 0.04%) and is constantly growing due to the continuous growth of petroleum products. It should be known that the trees absorb carbon dioxide and this is that their main function lies (and not as mistakenly believe that they only produce oxygen).
While a person is outdoors - there are no problems, but they begin when it is indoors. If a person is locked in a hermetic room without a bilge of fresh air, he will die not from the lack of oxygen, as the majority is mistaken, and from repeatedly exceeding the carbon dioxide level, which this person itself has developed in the lungs. Let us back up the problems of public transport ventilation (I will write about it separately) and turn our attention to urban apartments / Country houses, in which there is a massive ventilation.
At the same time, a person spends at least a third of his life in his home / apartment, and in reality half - you can not save on my own health!
2. The problem of increased maintenance of CO₂ in the air is especially relevant in the cold season, because In the summer, almost everyone is constantly open. And with the onset of cold weather, the windows open more and less, to end up with episodic ventilation. And, what coincidence, it is in the cold season that the depression, drowsiness and a decline of forces appear.
3. Previously, there was even such a tradition - sticking the slots on the windows in front of the cold. Often together with the windows and completely excluded the flow of fresh air to the house. I once again emphasize that fresh air is needed not because it has an oxygen necessary for breathing, but in order to reduce the excessive content of carbon dioxide to replace air indoors.
4. Many people think that they have a hood (in the apartments at least in the kitchen and in the bathroom), that's through it, the room will be ventilated. Yeah, in addition by installing plastic windows that are completely sealed. But how the air goes to the hood if you do not have a tributary in the form of either slots in the frames or open window? And with good plot usually pulls the air from the entrance.
5. It is worse only to deliver air conditioning in the form of a split system and use it with closed windows. Remember, when the air conditioner cannot close the windows! Here is a modern hermetic country house, which has no cracks in enclosing structures. And you do not need to be kept on the stories that the tree or aerated concrete "breathe" and therefore you can do not care for ventilation. Remember, under this term implies high vapor permeability of the material, and not the ability to serve fresh street air into the house.
6. Most is limited to the fan on the hood from the bathroom and the kitchen. Okay, turned on the fan, all windows and doors are closed in the house. What will be the result? That's right, there will be a vacuum in the house, because the new air is nowhere to take. So that natural ventilation worked, fresh air should flow into the house.
7. To measure carbon dioxide in the air, there are now relatively available sensors with an NDIR sensor. Not a dispersion infrared method (NDIR) is based on changing the intensity of IR radiation before and after absorbing in the infrared detector with election sensitivity. Initially, I was going to buy such a sensor on Aliexpress last year (then it cost about $ 100), but the growing price due to the growth of the dollar's course forced to think and search for alternative options. Suddenly, this sensor was found in Russia under the Russian brand for the same 100 dollars last year's course. Total, on Yandex.Market, I found the most advantageous offer and acquired a sensor at a price of 3500 rubles. The model is called MT8057. Of course, the sensor has an error, but it is not important when it comes to the fact that we are important to measure with excess of carbon dioxide concentration several times higher than the norm.
8. Closed plastic windows, air conditioners - all this nonsense compared to the gas stove in the apartment (for the photo I lit a gas burner, because To shoot, it had to be washed).
9. So all attention to the schedule. Kitchen 9. square meters, ceilings 3 meters high, opened door To the kitchen (!), Closed window, there is an extract with a natural motion (in the summer of a weak), one person. The sensor stands at an altitude of 1 meter from the floor, on the dinner table. "Normal" level of indoors without people about 600 ppm. One person comes - the level is instantly rises. It goes - falls. Comes again - again rises. And after that, includes one (!) Gas burner. The level of the SO is almost instantly rises above 2000 ppm. Anxiety! Open the window. We observe how slowly decreases the concentration of carbon dioxide in the air. And add 1-2 more people here. Even if you do not include a gas stove, then 3 adults do not perform heavy physical work Raise the level of CO₂ in the room to a critical mark in 30 minutes.
Cook on a gas stove? Be sure to open the window and turn on the exhaust (do both at the same time).
Included air conditioning? Be sure to open the window.
Just are you in the room? Be sure to open the window. And if there are many people in the room - open the window.
And at night, during sleep, the window must be kept open.
In short, you either have a difty ventilation channel, or a constantly open window.
10. As for trees and what they can be useful. Their essential function in the process of growth is the absorption of carbon dioxide. Few people think of why firewood is lit and where they have so much energy from them. So this energy in the form of carbon and accumulates in the tree trunk as a result of absorption of carbon dioxide. And the oxygen trees produce as a byproduct in the photosynthesis reaction.
11. Open the window in the warm season is not difficult and in general in the summer the problem is not as relevant (except for the use of air conditioners with closed windows). Problems begin in winter, because no one holds the open window, this is huge uncontrollable heat losses and will be tritely cold. That's exactly at this moment and it is worth raising an alarm. Health is invaluable.
The problem is very serious and is global. For example, before the fall last year, I did not think about the importance of ventilation for health: that in the apartment, that in a country house. If you look into the past, it is the regular autumn depression, drowsiness and a bad mood during the cold season of the year in an urban apartment confused to think towards what you need to learn from the city and build, because In the fall, the head was sick and there was a general weakness of the body while in the city. But as soon as I went to nature - the problem disappeared. I wrote off all this is not a shortage of sunlight, but it was not in it. In winter, I stopped keeping an open window (Coldly) and received a multiple excess of the apartment in the apartment.
The easiest and most affordable solution to the problem is to constantly keep an open window, or to ventilate focusing on the indicators from the CO₂ sensor. A normal level of CO₂ indoors can be considered a concentration to 1000 ppm if higher - it is necessary to ventilate urgently. An indirect indicator of high concentration of carbon dioxide in the air can be considered humidity. If without objective reasons and lowering the temperature in the room begins to increase the humidity - it means that the level of CO₂ is growing.
The danger of increased concentration of carbon dioxide in the air is that the human body reacts with a very large delay. By the time you felt that it was stuffy and need to ventilate in the room - you're at least half an hour were indoors with a high content of CO₂ in the air.
In the next post, I will tell you what problems are with ventilation in public transport (buses, trains, aircraft). And also show how to properly organize ventilation in a country house, which is for some reason for some reason.
To be continued.
Articles on the topic for independent study.
You already know that when you exhale the lungs, carbon dioxide comes out. But what do you know about this substance? Probably a little. Today I will answer all questions regarding carbon dioxide.
Definition
This substance under normal conditions is a colorless gas. In many sources, it can be called differently: and carbon oxide (IV), and carbon anhydride, and carbon dioxide, and carbon dioxide.
Properties
Carbon dioxide (Formula CO 2) is a colorless gas having acidic smell and taste soluble in water. If it should be cooled as it should be, then a snowy mass is formed, called dry ice (photo below), which is sublimated at a temperature of -78 o C.
It is one of the products of rotting or burning any organic matter. It dissolves in water only at a temperature of 15 ° C and only if the ratio of water: carbon dioxide is 1: 1. The density of carbon dioxide can be different, but under standard conditions it is 1.976 kg / m 3. This if it is in a gaseous form, and in other states (liquid / gaseous) the density value will also be different. This substance is acidic oxide, its addition to water leads to the preparation of coalic acid. If you connect carbon dioxide with any alkali, then as a result of the subsequent reaction, carbonates and bicarbonates are formed. This oxide cannot support burning, except for some exceptions. These are active metals, and when reactions of this species, they take oxygen.
Obtaining
Carbon dioxide and some more gases are distinguished in large quantities when alcohol is produced or natural carbonates decompose. Then the obtained gases are washed with dissolved potassium carbonate. Next, the absorption of carbon dioxide, the product of this reaction is a hydrocarbonate, when heated with a solution of which is obtained by the desired oxide.
But now it is successfully replaced by ethanolamine dissolved water, which absorbs the carbon monoxide contained in the smoke gas and gives it when heated. Also, this gas is a by-product of those reactions in which pure nitrogen is obtained, oxygen and argon. In the laboratory, some carbon dioxide it turns out when carbonates and bicarbonates interact with acids. It is also formed when the food soda and lemon juice react or the same sodium bicarbonate and vinegar (photo).
Application
The food industry cannot do without the use of carbon dioxide, where it is known as a preservative and a baking powder, which has an E290 code. It in the form of fluid contains any fire extinguisher.
Also, the oxide of tetravalent carbon, which stands out in the fermentation process, is good feeding aquarium plants. It is also contained in all the famous gas production, which many are quite often buying at the grocery store. Welding with wire occurs in a carbon dioxide, but if the temperature of this process is very high, it is accompanied by dissociation of carbon dioxide, in which oxygen is distinguished, oxidizing metal. Then welding does not work out without deoxidizers (manganese or silicon). Carbon dioxide is pumped by bicycle wheels, it is present in the balllors of pneumatic weapons (such a variety is called gas). Also, this oxide in a solid state, called dry ice, is needed as a refrigerant in trade, scientific research And when fixing some technique.
That is what the carbon dioxide is useful for humans. And not only in industry, he plays and important biological role: With it, gas exchange can not occur, regulation of vascular tone, photosynthesis and many other natural processes. But his oversupplication or shortage in the air can adversely affect the physical condition of all living organisms.
Carbon dioxide, or carbon dioxide, or CO 2 is one of the most common gaseous substances on Earth. He surrounds us throughout our life. Carbon dioxide does not have color, taste and smell and is not felt by a person.
It is an important participant in the metabolism of living organisms. The gas itself does not poison, but does not support breathing, therefore the excess of its concentration leads to a deterioration in the supply of body tissues with oxygen and to suffocation. Carbon dioxide is widely used in everyday life and in industry.
What is carbon dioxide
For atmospheric pressure and the room temperature of carbon dioxide is in a gaseous state. This is the most common form of his form, in it he participates in the process of breathing, photosynthesis and metabolism of living organisms.
When cooling to -78 ° C, it, bypassing the liquid phase, crystallizes and forms the so-called "dry ice", widely used as a safe refrigerant in the food and chemical industry and in street trade and refrigerated transport.
Under special conditions - pressure in tens of atmospheres - carbon dioxide goes into liquid state of aggregation. This happens on sea Dn.at a depth of more than 600 m.
Gas carbon dioxide properties
In the 17th century, Jean-Batist Van Gelmont from Flanders opened carbon dioxide and determined his formula. A detailed study and a description was made by century later by Scottish Joseph Blake. He explored the properties of carbon dioxide and conducted a series of experiments, in which he has proven that it is distinguished by animal breathing.
The composition of the substance molecule includes one carbon atom and two oxygen atoms. Chemical formula Carbon dioxide is written as CO 2
Under normal conditions, it does not have taste, color and smell. Only inhaling his large amount, a person feels an acidic taste. It gives coalic acid formed in small doses when dissolving carbon dioxide in saliva. This feature is used to prepare carbonated drinks. Bubbles in champagne, concoction, beer and lemonade - this is a carbon dioxide formed as a result of natural fermentation processes or added to the drink artificially.
The density of carbon dioxide is more air density, so in the absence of ventilation, it accumulates below. It does not support oxidative processes, such as breathing and burning.
Therefore, carbon dioxide is used in fire extinguishers. This property of carbon dioxide is illustrated by focus - the burning candle is lowered in the "empty" glass, where it goes out. In fact, the glass is filled with CO 2.
Carbon dioxide in nature Natural sources
Such sources include oxidative processes of different intensity:
- Breathing of living organisms. From the school course of chemistry and botanists, everyone remembers that during photosynthesis of plants absorb carbon dioxide and excrete oxygen. But not everyone remembers that this is happening only during the day, with a sufficient level of lighting. In the dark, the plants, on the contrary, absorb oxygen and isolated carbon dioxide. So an attempt to improve the air quality in the room, turning it into thickets of ficuses and Gerani can play a dick joke.
- Eruption and other volcanic activity. CO 2 is thrown out of the depths of the land mantle along with volcanic gases. In the valleys next to the sources of gas eruptions, so much that, accumulating in lowlands, he raises the suffocations of animals and even people. A few cases in Africa are known when whole villages have been torn.
- Burning and rotting organics. The burning and rotting is the same oxidation reaction, but flowing at different speeds. Carbon-rich decaying organic remains of plants and animals, forest fires and smoldering peatlands are all sources of carbon dioxide.
- The most large natural storage CO 2 is the waters of the World Ocean in which it is dissolved.
For millions of years, the evolution based on carbon compounds of life on Earth in various sources has accumulated many billions tons of carbon dioxide. Its simultaneous release into the atmosphere will lead to the death of the whole living on the planet due to the impossibility of breathing. It is good that the likelihood of such a one-step emission is striving for zero.
ANDbowful carbon dioxide sources
Carbon dioxide enters the atmosphere and as a result of human livelihoods. The most active sources in our time are considered:
- Industrial emissions occurring during the combustion of fuel at power plants and in technological installations
- Exhaust gases of internal combustion engines of vehicles: cars, trains, airplanes and ships.
- Agricultural waste - rotting manure in large livestock complexes
In addition to direct emissions, there is an indirect effect of a person for the CO 2 content in the atmosphere. This is a mass deforestation of forests in the tropical and subtropical zone, primarily in the Amazon Pool.
Despite the fact that the Earth's atmosphere contains less than a carbon dioxide, it has an increasing effect on climate and natural phenomena. Carbon dioxide participates in the creation of the so-called greenhouse effect By absorbing thermal radiation of the planet and holding this heat in the atmosphere. This leads to a gradual, but very threatening increase in the average annual temperature of the planet, the melting of mountain glaciers and polar ice hats, the growth of the world's ocean level, the flooding of coastal regions and the worsening of the climate in the distant countries from the sea.
It is significant that against the background of general warming on the planet there is a significant redistribution of air masses and marines, and in separate regions the average annual temperature does not increase, and decreases. This gives trumps into the hands of the critics of the theory of global warming, accusing her supporters in taking the facts and manipulation by public opinion in favor of certain political centers of influence and financial and economic interests.
Humanity is trying to take control of carbon dioxide in the air, Kyoto and Paris Protocols have been signed, imposing certain obligations on national economies. In addition, many leading car producers have announced a folding of models with internal combustion engines to 2020-25 years and transition to hybrids and electric vehicles. However, some leading economies in the world, such as China and the United States, are not in a hurry to fulfill the old and take on new commitments, motivating this threat to life in their countries.
Carbon dioxide and we: what is dangerous co 2
Carbon dioxide is one of the metabolic products in the human body. It plays a large role in driving and supplying blood organs. The growth of CO 2 content in the blood causes the extension of vessels that can transport more oxygen to tissues and organs. Similarly, the respiratory system is agreed towards greater activity if the concentration of carbon dioxide in the body grows. This property is used in the devices of artificial ventilation of the lungs in order to raise their own patient respiration to greater activity.
In addition to the above-mentioned benefit, the excess of the concentration of CO 2 can bring the body and harm. Increased content in the inhaled air leads to nausea, headache, suffocation and even to loss of consciousness. The body protests against carbon dioxide and gives a person a signals. With a further increase in concentration, oxygen starvation is developing, or hypoxia. CO 2 interferes with oxygen to be connected to hemoglobin molecules, which are moved by the connected gases on the circulatory system. Oxygen starvation leads to a decrease in performance, weakening the reaction and ability to analyze the situation and making decisions, apathy and can lead to death.
Such concentrations of carbon dioxide, unfortunately, are achievable not only in close mines, but also in poorly ventilated school classes, concert halls, office space and vehicles - everywhere, where in a closed space without sufficient air exchange with environmental accumulate a large number of of people.
Basic application
CO 2 is widely used in industry and in everyday life - in fire extinguishers and for the manufacture of soda, for cooling products and to create an inert medium during welding.
The use of carbon dioxide is noted in such industries as:
- to clean the surfaces of dry ice.
Pharmaceutics
- for chemical synthesis of drug components;
- creating an inert atmosphere;
- normalization of index pH of production waste.
Food industry
- production of carbonated drinks;
- packaging of food in an inert atmosphere to extend the shelf life;
- decaffelation of coffee beans;
- freeze or cooling products.
Medicine, analyzes and ecology
- Creating a protective atmosphere with extensive operations.
- The inclusion in the breathing mixtures as a breathing stimulator.
- In chromatographic analyzes.
- Maintain pH level in liquid production waste.
Electronics
- Cooling electronic components and devices when testing for temperature durability.
- Abrasive cleaning in microelectronics (in solid phase).
- Cleansing agent in the production of silicon crystals.
Chemical industry
It is widely used in chemical synthesis as a reagent and as a temperature controller in the reactor. CO 2 is excellent for disinfection of liquid waste with a low pH index.
It is also used to drain polymer substances, plant or animal fibromaterials, in cellulose production to normalize the pH level as components of the main process and its waste.
Metallurgical industry
CO 2 in Metallurgy mainly serves as an ecology, protection of nature from harmful emissions by neutralization:
- In ferrous metallurgy - to neutralize melting gases and for the bottom mixing of the melt.
- In non-ferrous metallurgy in the production of lead, copper, nickel and zinc - for neutralizing gases during the transportation of a bucket with a melt or hot ingots.
- As a reducing agent when organizing the turnover of acidine mine waters.
Carbonate welding
The variety of welding under the flux is welding in carbon dioxide. The operations of welding work with carbon dioxide are carried out by a melting electrode and is distributed in the process of installation work, eliminate defects and correction of parts with thin walls.
As you know, we all come from childhood. And one of the sweet memories of the first years of life, which we often have passed throughout the whole life, is the taste of sweet soda from the bottle. In order for children and adults to enjoy their favorite carbonated drinks, and need carbon dioxide in cylinders,which through simple manipulations fills the contents of the bottle by magic bubbles. And there is no greater pleasure than exploding bubbles in the nose, in the mouth, the stomach ... We are growing, growing up. We begin to give preference to other carbonated and not carbonated, but also "beating" in the nose and head, drinks. But with age, it often remains a mystery to question:
But what about carbon dioxide in the cylinders turns out to be in a bottle?
Carbon dioxide - gas without color with a slightly acidic taste, not toxic, having many names such as: carbon dioxide, carbon dioxide, coal anhydride, CO2 and others. This gas does not support breathing and in large concentrations causes suffocations, but is essential in the process of metabolism of living cells. It is obtained as a byproduct, in the production of alcohol, ammonia or fuel combustion. Gas density, under normal conditions, is 1.98 g / l. Therefore, carbon dioxide in cylinders under pressure is about 70 atmospheres, for greater capacity. Gas compression use special equipment. At the production of gashed water into bottles with a drink, immediately before blockage, add acid from the cylinder. And if we release carbonate into the atmosphere, part of it turn into dry ice. But the food industry is not the only sphere where carbon dioxide is used.
Where is still used carbon dioxide in cylinders?
Modern construction is fully based on metal structures. To get a durable metal frame, welding needed. Carbon dioxide is an acid oxide, which, when interacting with water, forms coalic acid. It reaches with alkalis with the release of bicarbonates and carbonates. On this property, it is based on its use in the welding process: carbon dioxide in cylindersit turns into a protective layer, which ensures the strength of the welding seam. Also, carbon dioxide fill fire extinguishers that are designed to extinguish electrical installations.
And if you decide to buy a balloon for gases, remember that it is presented to its transportation and use special requirements. Work with carbon dioxide can be dangerous, for example, when hitting hands, burns may form.
Where can I buy a balloon for gases?
Acquisition of cylinders for storing and transporting gases from unknown sellers who cannot confirm their rights documented does not guarantee their safe application! Safely buy balloon for gasesfrom proven manufacturers can be from us. Our carbon dioxide tranquits are an industrial volume of 50 liters. And small spam cans. Their safe operation is ensured by the manufacture, taking into account all the requirements of the guests.
Definition
Carbon dioxide (carbon dioxide) Under normal conditions, colorless gas, about 1.5 times heavier than air, so that it can be overflowed as a liquid, from one vessel to another.
The mass of 1 L CO 2 under normal conditions is 1.98 g. The solubility of carbon dioxide in water is small: 1 The volume of water at 20 o C dissolves 0.88 volume CO 2, and at 0 o C - 1.7 volumes.
Under the pressure of about 0.6 MPa carbon dioxide at room temperature turns into a liquid. Liquid carbon dioxide is stored in steel cylinders. With a rapid pouring, it is absorbed due to evaporation so much heat, which CO 2 turns into a solid white snow-shaped mass, which, without melting, is sublimated at -78.5 o C.
The CO 2 solution in water has a sour taste and has a weakly acidic reaction due to the presence in the solution of small amounts of coalic acid H 2 CO 3, resulting from a reversible reaction:
CO 2 + H 2 O↔h 2 CO 3.
Some properties of carbon dioxide are presented in the table below:
Getting carbon dioxide
Carbon dioxide in small quantities is obtained by the action of acids into carbonates:
Caco 3 + 2HCl \u003d CaCl 2 + H 2 O + CO 2.
On an industrial scale CO 2 is mainly obtained as a by-product in the process of ammonia synthesis:
CH 4 + 2H 2 O \u003d CO 2 + 4H 2;
CO + H 2 O \u003d CO 2 + H 2.
In addition, large amounts of carbon dioxide are obtained during limestone firing:
Caco 3 \u003d Cao + CO 2.
Chemical properties of carbon dioxide
Carbon dioxide exhibits acidic properties: reacts with messengers, ammonia hydrate. Restores active metals, hydrogen, carbon.
CO 2 + NaOH Dilute \u003d NaHCO 3;
CO 2 + 2NAOH CONC \u003d Na 2 CO 3 + H 2 O;
CO 2 + BA (OH) 2 \u003d Baco 3 + H 2 O;
CO 2 + BACO 3 + H 2 O \u003d BA (HCO 3) 2;
CO 2 + NH 3 × H 2 O \u003d NH 4 HCO 3;
CO 2 + 4H 2 \u003d CH 4 + 2H 2 O (T \u003d 200 o C, Kat. Cu 2 O);
CO 2 + C \u003d 2CO (T\u003e 1000 o C);
CO 2 + 2MG \u003d C + 2MGO;
2CO 2 + 5CA \u003d CAC 2 + 4CAO (T \u003d 500 O C);
2CO 2 + 2NA 2 O 2 \u003d 2NA 2 CO 3 + O 2.
Application of carbon dioxide
Carbon dioxide is used in obtaining soda by ammonia-chloride method, for the synthesis of carbamide, to obtain carbonic acid salts, as well as for the hydration of fruit and mineral waters and other beverages.
Hard carbon dioxide called "dry ice" is used to cool the perishable products, for the production and conservation of ice cream, as well as many other cases when low temperature is obtained.
Examples of solving problems
Example 1.
Example 2.
| The task | What volume and which mass of carbon dioxide will allocate with thermal decomposition of calcium carbonate weighing 45.4 g? |
| Decision | We write the thermal decomposition equation of calcium carbonate: Caco 3 \u003d Cao + CO 2. Find the amount of calcium carbonate substance: n (Caco 3) \u003d M (CaCO 3) / M (Caco 3); M (Caco 3) \u003d Ar (Ca) + Ar (C) + 3 × AR (O) \u003d 40 + 12 + 3 × 16 \u003d 100 g / mol; n (Caco 3) \u003d 45.4 / 100 \u003d 0.454 mol. According to the N (CaCO 3) reaction equation: N (CO 2) \u003d 1: 1, therefore n (Caco 3) \u003d n (CO 2) \u003d 0.454 mol. Calculate the mass and volume of highlighted carbon dioxide: V (CO 2) \u003d V M × n (CO 2) \u003d 22.4 × 0.454 \u003d 10.2 l; m (CO 2) \u003d N (CO 2) × M (CO 2); M (CO 2) \u003d Ar (C) + 2 × AR (O) \u003d 12 + 2 × 16 \u003d 44 g / mol; m (CO 2) \u003d 0.454 × 44 \u003d 20 g |
| Answer | The mass of carbon dioxide is 20 g, the volume is 10.2 liters. |
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