Bullet trains are back on the political agenda. As the major parties look for ways to stimulate the economy after the COVID-19 crisis, Labor is again spruiking its vision of linking Melbourne, Sydney, Canberra and Brisbane ...
Environment
4 hours ago
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Given the present-day rate of global sea-level rise, remaining marshes in the Mississippi Delta are likely to drown, according to a new Tulane University study.
Environment
May 22, 2020
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In a step toward a more sustainable, zero-carbon future, McCourt School assistant professor Raphael Calel and UC Santa Barbara assistant professor Paasha Mahdavi propose two ideas that would encourage companies to capture ...
Environment
May 21, 2020
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Nearly all the countries of the world ratified the Paris Agreement in 2016. The accord aims to limit the increase of the world's temperature to less than 2 degrees Celsius above pre-industrial temperatures. To do this, global ...
Environment
May 19, 2020
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Carbon dioxide (CO2) emissions in European cities has reduced by up to 75% due to the COVID-19 lockdown, with a 59% reduction in London, a new study has revealed.
Environment
May 19, 2020
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China's implementation of a national carbon trading market to reduce greenhouse gas (GHG) emissions requires reliable and timely information on GHG sources and impacts. Recent GHG monitoring and modeling studies provide new ...
Environment
May 18, 2020
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Professor Yutaka Amao of the Osaka City University Artificial Photosynthesis Research Center and Ryohei Sato, a 1st year Ph.D. student of the Graduate School of Science majoring in Physics and Chemistry, reveal that the catalyst ...
Materials Science
May 18, 2020
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Scientists at the University of South Carolina and Columbia University have developed a faster way to design and make gas-filtering membranes that could cut greenhouse gas emissions and reduce pollution.
Materials Science
May 15, 2020
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Antarctica's king penguins emit such copious amounts of nitrous oxide, or laughing gas, via their faeces that researchers went a little "cuckoo" studying them, according to a Danish scientific study published Thursday.
Environment
May 14, 2020
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The vapor that plants emit when they breathe serves to lower land surface temperature, much like watering the yard on a hot day. Until now, the greenhouse effect has been blamed for the rise in global temperature. But an ...
Environment
May 14, 2020
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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.
This text uses material from Wikipedia, licensed under CC BY-SA
