Consumer & Gadgets

Researchers find smart faucets could aid in water conservation

Barely hidden from his study participants, William Jou, a former graduate student in mechanical engineering at Stanford University, pulled off a ruse straight out of The Wizard of Oz. Except, instead of impersonating a great ...

Energy & Green Tech

Growth of wind energy points to future challenges, promise

Advances in adapting the technology for cold climates and offshore use and better methods for predicting wind conditions have fanned significant growth of the use of wind turbines for electricity in the last 40 years. A new ...

Engineering

New technology: Hygienic beer caps

UV light inactivates germs in drinking water. Until now, the disinfection process relied on mercury-vapor lamps, which emit light in the UV spectrum. However, mercury is a heavy metal that affects human health and the environment. ...

Engineering

How roads can help cool sizzling cities

Special permeable concrete pavement can help reduce the "urban heat island effect" that causes cities to sizzle in the summer, according to a Rutgers-led team of engineers.

Hi Tech & Innovation

French 'flyboard' daredevil to make new Channel bid

A Frenchman who has captured the country's imagination with his jet-powered "flyboard" will make a new bid to cross the English Channel after a failed first attempt last week, his team said on Tuesday.

Engineering

Researchers pave the way to salt-resistant concrete

Pavements could soon be saved from some of the ravages of the winter chill thanks to a new type of low-cost concrete that absorbs significantly less of the salt that gets spread on it annually.

Energy & Green Tech

Water solutions without a grain of salt

Monash University researchers have developed technology that can deliver clean water to thousands of communities worldwide. This solar steam generation system produces clean water from salty (ocean) water with almost 100 ...

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Water

Water is a ubiquitous chemical substance, composed of hydrogen and oxygen, that is essential for the survival of many known forms of life. In typical usage, water refers only to its liquid form or state, but the substance also has a solid state, ice, and a gaseous state, water vapor or steam. Water covers 71% of the Earth's surface. On Earth, it is found mostly in oceans and other large water bodies, with 1.6% of water below ground in aquifers and 0.001% in the air as vapor, clouds (formed of solid and liquid water particles suspended in air), and precipitation. Saltwater oceans hold 97% of surface water, glaciers and polar ice caps 2.4%, and other land surface water such as rivers, lakes and ponds 0.6%. A very small amount of the Earth's water is contained within biological bodies and manufactured products. Other water is trapped in ice caps, glaciers, aquifers, or in lakes, sometimes providing fresh water for life on land.

Water moves continually through a cycle of evaporation or transpiration (evapotranspiration), precipitation, and runoff, usually reaching the sea. Winds carry water vapor over land at the same rate as runoff into the sea. Over land, evaporation and transpiration contribute to the precipitation over land.

Clean, fresh drinking water is essential to human and other lifeforms. Access to safe drinking water has improved steadily and substantially over the last decades in almost every part of the world. There is a clear correlation between access to safe water and GDP per capita. However, some observers have estimated that by 2025 more than half of the world population will be facing water-based vulnerability. Water plays an important role in the world economy, as it functions as a solvent for a wide variety of chemical substances and facilitates industrial cooling and transportation. Approximately 70 percent of freshwater is consumed by agriculture.

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