News tagged with greenhouse
From lemons to lemonade: Reaction uses carbon dioxide to make carbon-based semiconductor
(Phys.org) -- A materials scientist at Michigan Technological University has discovered a chemical reaction that not only eats up the greenhouse gas carbon dioxide, it also creates something useful. And, by ...
May 21, 2012 |
4.7 / 5 (89) |
33
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Solar thermal process produces cement with no carbon dioxide emissions
(Phys.org) -- While the largest contributor to anthropogenic greenhouse gas emissions is the power industry, the second largest is the more often overlooked cement industry, which accounts for 5-6% of all ...
Apr 10, 2012 |
4.6 / 5 (25) |
22
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Biggest jump ever seen in global warming gases
(AP) -- The global output of heat-trapping carbon dioxide jumped by the biggest amount on record, the U.S. Department of Energy calculated, a sign of how feeble the world's efforts are at slowing man-made ...
Nov 03, 2011 |
3.2 / 5 (32) |
29
Global warming caused by greenhouse gases delays natural patterns of glaciation
Unprecedented levels of greenhouse gases in the Earth's atmosphere are disrupting normal patterns of glaciation, according to a study co-authored by a University of Florida researcher and published online Jan. 8 in Nature Ge ...
Space & Earth / Earth Sciences
Jan 08, 2012 |
3.5 / 5 (29) |
114
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World has five years to avoid severe warming: IEA
The world has just five years to avoid being trapped in a scenario of perilous climate change and extreme weather events, the International Energy Agency (IEA) warned on Wednesday.
Nov 09, 2011 |
3.9 / 5 (22) |
62
Canadian firm bids to commercialize fusion reactor
In the race against world governments and the wealthiest companies to commercialize a nuclear fusion reactor, a small, innovative Canadian firm is hoping to bottle and sell the sun's energy.
Technology / Energy & Green Tech
Nov 30, 2011 |
4 / 5 (21) |
79
Global extinction: Gradual doom is just as bad as abrupt
A painstakingly detailed investigation shows that mass extinctions need not be sudden events. The deadliest mass extinction of all took a long time to kill 90 percent of Earth's marine life, and it killed ...
Space & Earth / Earth Sciences
Feb 03, 2012 |
4.2 / 5 (20) |
0
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New catalyst for safe, reversible hydrogen storage
(PhysOrg.com) -- Scientists at the Brookhaven National Laboratory and collaborators have developed a new catalyst that reversibly converts hydrogen gas and carbon dioxide to a liquid under very mild conditions. ...
Mar 18, 2012 |
4.7 / 5 (15) |
34
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Extreme summer temperatures occur more frequently: study
(PhysOrg.com) -- Extreme summer temperatures are already occurring more frequently in the United States, and will become normal by mid-century if the world continues on a business as usual schedule of emitting ...
Feb 15, 2012 |
3.2 / 5 (21) |
64
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Thawing tundra a new climate threat
(PhysOrg.com) -- A significant source of greenhouse gases has started leaking into the Earth's atmosphere from an unlikely place. Above the Arctic Circle, land frozen for tens of thousands of years has begun ...
Jan 20, 2012 |
4.2 / 5 (15) |
11
Advanced power-grid research finds low-cost, low-carbon future in West
The least expensive way for the Western U.S. to reduce greenhouse gas emissions enough to help prevent the worst consequences of global warming is to replace coal with renewable and other sources of energy ...
Technology / Energy & Green Tech
Apr 03, 2012 |
4.2 / 5 (14) |
73
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Greenhouse gases to overpower ozone hole
(PhysOrg.com) -- One set of human-created gases is starting to relinquish its hold on Antarctic climate as another group of emissions produced by human activity is starting to take hold, according to a paper ...
Space & Earth / Earth Sciences
Nov 02, 2011 |
4.4 / 5 (13) |
14
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Greenhouse gases soar; no signs warming is slowed
(AP) -- Heat-trapping greenhouse gases in the atmosphere are building up so high, so fast, that some scientists now think the world can no longer limit global warming to the level world leaders have agreed upon as safe.
Nov 21, 2011 |
4.4 / 5 (13) |
61
Abrupt permafrost thaw increases climate threat
As the Arctic warms, greenhouse gases will be released from thawing permafrost faster and at significantly higher levels than previous estimates, according to survey results from 41 international scientists ...
Space & Earth / Earth Sciences
Nov 30, 2011 |
4.4 / 5 (13) |
6
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Nasa study solves case of Earth's 'missing energy'
(PhysOrg.com) -- Two years ago, scientists at the National Center for Atmospheric Research in Boulder, Colo., released a study claiming that inconsistencies between satellite observations of Earth's heat and ...
Space & Earth / Earth Sciences
Jan 30, 2012 |
4.1 / 5 (14) |
12
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Greenhouse
A greenhouse (also called a glasshouse) is a building in which plants are grown. These structures range in size from small sheds to very large buildings. A miniature greenhouse is known as a cold frame.
A greenhouse is a structure with different types of covering materials, such as a glass or plastic roof and frequently glass or plastic walls; it heats up because incoming visible solar radiation (for which the glass is transparent) from the sun is absorbed by plants, soil, and other things inside the building. Air warmed by the heat from hot interior surfaces is retained in the building by the roof and wall. In addition, the warmed structures and plants inside the greenhouse re-radiate some of their thermal energy in the infra-red, to which glass is partly opaque, so some of this energy is also trapped inside the glasshouse. However, this latter process is a minor player compared with the former (convective) process. Thus, the primary heating mechanism of a greenhouse is convection. This can be demonstrated by opening a small window near the roof of a greenhouse: the temperature drops considerably. This principle is the basis of the autovent automatic cooling system. Thus, the glass used for a greenhouse works as a barrier to air flow, and its effect is to trap energy within the greenhouse. The air that is warmed near the ground is prevented from rising indefinitely and flowing away.
Although there is some heat loss due to thermal conduction through the glass and other building materials, there is a net increase in energy (and therefore temperature) inside the greenhouse.
Greenhouses can be divided into glass greenhouses and plastic greenhouses. Plastics mostly used are PEfilm and multiwall sheet in PC or PMMA. Commercial glass greenhouses are often high tech production facilities for vegetables or flowers. The glass greenhouses are filled with equipment like screening installations, heating, cooling, lighting and may be automatically controlled by a computer.
For more information about Greenhouse, read the full article at
Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
