News tagged with carbon dioxide

Related topics: climate change , greenhouse gas , global warming , greenhouse gases , atmosphere

New device to monitor lung function in space

A new method of collecting blood from the ear, currently part of an interactive exhibition at the Science Museum, could be used to monitor lung function in space. Less invasive, faster and more accurate than current methods, ...

Jul 23, 2014
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Laser-assisted drug delivery is evolving

(HealthDay)—Laser-assisted drug delivery can enhance the permeation of topically applied agents, according to a review published in the April issue of Lasers in Surgery and Medicine.

Apr 27, 2014
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Ablative carbon dioxide laser effective for rhinophyma

(HealthDay)—Good cosmetic outcomes are possible using fractionated ablative carbon dioxide laser therapy for mild-to-moderate cases of rhinophyma, according to research published online Oct. 5 in Lasers in ...

Oct 17, 2013
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Why kids breathe easier in summer

A good night's sleep is important to our children's development. But with the first day of school just passed, many children are at increased risk for sleep breathing disorders that can impair their mental ...

Sep 17, 2013
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Carbon dioxide

Carbon dioxide (chemical formula: CO2) is a chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom. It is a gas at standard temperature and pressure and exists in Earth's atmosphere in this state.

Carbon dioxide is used by plants during photosynthesis to make sugars, which may either be consumed in respiration or used as the raw material to produce other organic compounds needed for plant growth and development. It is produced during respiration by plants, and by all animals, fungi and microorganisms that depend either directly or indirectly on plants for food. It is thus a major component of the carbon cycle. Carbon dioxide is generated as a by-product of the combustion of fossil fuels or the burning of vegetable matter, among other chemical processes. Large amounts of carbon dioxide are emitted from volcanoes and other geothermal processes such as hot springs and geysers and by the dissolution of carbonates in crustal rocks.

As of March 2009[update], carbon dioxide in the Earth's atmosphere is at a concentration of 387 ppm by volume. Atmospheric concentrations of carbon dioxide fluctuate slightly with the change of the seasons, driven primarily by seasonal plant growth in the Northern Hemisphere. Concentrations of carbon dioxide fall during the northern spring and summer as plants consume the gas, and rise during the northern autumn and winter as plants go dormant, die and decay. Carbon dioxide is a greenhouse gas as it transmits visible light but absorbs strongly in the infrared and near-infrared.

Carbon dioxide has no liquid state at pressures below 5.1 atmospheres. At 1 atmosphere (near mean sea level pressure), the gas deposits directly to a solid at temperatures below −78 °C and the solid sublimes directly to a gas above −78 °C. In its solid state, carbon dioxide is commonly called dry ice.

CO2 is an acidic oxide: an aqueous solution turns litmus from blue to pink. It is the anhydride of carbonic acid, an acid which is unstable and is known to exist only in aqueous solution.

CO2 is toxic in higher concentrations: 1% (10,000 ppm) will make some people feel drowsy. Concentrations of 7% to 10% cause dizziness, headache, visual and hearing dysfunction, and unconsciousness within a few minutes to an hour.

This text uses material from Wikipedia licensed under CC BY-SA