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Aethalometer
An aethalometer is an instrument for measuring the concentration of optically absorbing (‘black’) suspended particulates in a gas colloid stream; commonly visualized as smoke or haze, often seen in ambient air under polluted conditions. The word aethalometer is derived from the Classical Greek verb ''aethaloun'', meaning "to blacken with soot". The aethalometer, a device used for measuring black carbon in atmospheric aerosols, was initially deployed in 1980 and was first commercialized by Magee Scientific. Principle of operation The gas stream (frequently ambient air) passes through a filter material which traps the suspended particulates, creating a deposit of increasing density. A light beam projected through the deposit is attenuated by those particles which are absorbing (‘black’) rather than scattering (‘white’). Measurements are made at successive regular time intervals. The increase in attenuation from one measurement to the next is proportional to the incr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aethalometer Exterior
An aethalometer is an instrument for measuring the concentration of optically absorbing (‘black’) Suspension (chemistry), suspended particulates in a gas colloid stream; commonly visualized as smoke or haze, often seen in ambient air under polluted conditions. The word aethalometer is derived from the Classical Greek verb ''aethaloun'', meaning "to blacken with soot". The aethalometer, a device used for measuring black carbon in atmospheric aerosols, was initially deployed in 1980 and was first commercialized by Magee Scientific. Principle of operation The gas stream (frequently ambient air) passes through a Filter paper, filter material which traps the suspended particulates, creating a deposit of increasing density. A light beam projected through the deposit is Attenuation, attenuated by those particles which are Light absorption, absorbing (‘black’) rather than Light scattering, scattering (‘white’). Measurements are made at successive regular time intervals. The i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aethalometer Interior
An aethalometer is an instrument for measuring the concentration of optically absorbing (‘black’) suspended particulates in a gas colloid stream; commonly visualized as smoke or haze, often seen in ambient air under polluted conditions. The word aethalometer is derived from the Classical Greek verb ''aethaloun'', meaning "to blacken with soot". The aethalometer, a device used for measuring black carbon in atmospheric aerosols, was initially deployed in 1980 and was first commercialized by Magee Scientific. Principle of operation The gas stream (frequently ambient air) passes through a filter material which traps the suspended particulates, creating a deposit of increasing density. A light beam projected through the deposit is attenuated by those particles which are absorbing (‘black’) rather than scattering (‘white’). Measurements are made at successive regular time intervals. The increase in attenuation from one measurement to the next is proportional to the incr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tihomir Novakov
Tihomir Novakov, also known as Tica Novakov (March 16, 1929 – January 2, 2015) was a Serbian-born American physicist. As a scientist, Novakov is known for his black carbon, air quality, and climate change research. James Hansen dubbed him "the godfather of black carbon". Early life Novakov was born in Sombor, Serbia, in 1929. His father was a veterinarian and his mother was a homemaker. While in high school, Novakov began to build X-ray tubes and radios, furthering his scientific knowledge on his own. After graduating from the University of Belgrade with a PhD in nuclear physics, he taught at the University of Belgrade and worked at the Vinča Nuclear Institute. Novakov migrated to the United States in 1963 and began working as a research scientist at the Lawrence Berkeley National Laboratory. He later founded an Aerosol Research Group which traveled the world conducting research on climate change. Career In the late 1960s and early 1970s, Novakov's group was the first to appl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Smoke
Smoke is an aerosol (a suspension of airborne particulates and gases) emitted when a material undergoes combustion or pyrolysis, together with the quantity of air that is entrained or otherwise mixed into the mass. It is commonly an unwanted by-product of fires (including stoves, candles, internal combustion engines, oil lamps, and fireplaces), but may also be used for pest control ( fumigation), communication ( smoke signals), defensive and offensive capabilities in the military ( smoke screen), cooking, or smoking (tobacco, cannabis, etc.). It is used in rituals where incense, sage, or resin is burned to produce a smell for spiritual or magical purposes. It can also be a flavoring agent and preservative. Smoke inhalation is the primary cause of death in victims of indoor fires. The smoke kills by a combination of thermal damage, poisoning and pulmonary irritation caused by carbon monoxide, hydrogen cyanide and other combustion products. Smoke is an aerosol (or mi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Black Carbon
Black carbon (BC) is the light-absorbing refractory form of Chemical_element, elemental carbon remaining after pyrolysis (e.g., charcoal) or produced by incomplete combustion (e.g., soot). Tihomir Novakov originated the term black carbon in the 1970s, after identifying black carbon as fine Particulates, particulate matter (PM ≤ 2.5 μm aerodynamic diameter) in aerosols. Aerosol black carbon occurs in several linked forms. Formed through the incomplete combustion of fossil fuels, biofuel, and biomass, black carbon is one of the main types of soot particle in both human impact on the environment, anthropogenic and naturally occurring soot. As soot, black carbon causes disease and premature death. Because of these human health impacts, many countries have worked to reduce their emissions. In climatology, aerosol black carbon is a climate forcing agent contributing to Climate change, global warming. Black carbon warms the Earth by absorbing sunlight and heating the atmosp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diesel Exhaust
Diesel exhaust is the exhaust gas produced by a diesel engine, plus any contained particulates. Its composition may vary with the fuel type, rate of consumption or speed of engine operation (e.g., idling or at speed or under load), and whether the engine is in an on-road vehicle, farm vehicle, locomotive, marine vessel, or stationary generator or other application. Diesel exhaust causes lung cancer and other diseases such as asthma, and many premature deaths. Methods exist to reduce nitrogen oxides (NOx) and particulate matter (PM) in the exhaust. Some countries have set a date to stop selling diesel vehicles, and some city centres will ban diesel cars. Composition The primary products of petroleum fuel combustion in air are carbon dioxide, water, and nitrogen. The other components exist primarily from incomplete combustion and pyrosynthesis. While the distribution of the individual components of raw (untreated) diesel exhaust varies depending on factors like load, engi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soot
Soot ( ) is a mass of impure carbon particles resulting from the incomplete combustion of hydrocarbons. Soot is considered a hazardous substance with carcinogenic properties. Most broadly, the term includes all the particulate matter produced by this process, including black carbon and residual pyrolysed fuel particles such as coal, cenospheres, charred wood, and petroleum coke classified as cokes or char. It can include polycyclic aromatic hydrocarbons and heavy metals like mercury. Soot causes various types of cancer and lung disease. Terminology Definition Among scientists, exact definitions for soot vary, depending partly on their field. For example, atmospheric scientists may use a different definition compared to toxicologists. Soot's definition can also vary across time, and from paper to paper even among scientists in the same field. A common feature of the definitions is that soot is composed largely of carbon based particles resulting from the incomplete burni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Long-range Transport
Persistent organic pollutants (POPs) are organic compounds that are resistant to degradation through chemical, biological, and photolytic processes. They are toxic and adversely affect human health and the environment around the world. Because they can be transported by wind and water, most POPs generated in one country can and do affect people and wildlife far from where they are used and released. The effect of POPs on human and environmental health was discussed, with intention to eliminate or severely restrict their production, by the international community at the Stockholm Convention on Persistent Organic Pollutants in 2001. Most POPs are pesticides or insecticides, and some are also solvents, pharmaceuticals, and industrial chemicals. Although some POPs arise naturally (e.g. from volcanoes), most are man-made. The "dirty dozen" POPs identified by the Stockholm Convention include aldrin, chlordane, dieldrin, endrin, heptachlor, HCB, mirex, toxaphene, PCBs, DDT, dioxins ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Climate Change In The Arctic
Due to climate change in the Arctic, this polar region is expected to become "profoundly different" by 2050. The speed of change is "among the highest in the world", with the rate of warming being 3-4 times faster than the global average. This warming has already resulted in the profound Arctic sea ice decline, the accelerating melting of the Greenland ice sheet and the thawing of the permafrost Permafrost () is soil or underwater sediment which continuously remains below for two years or more; the oldest permafrost has been continuously frozen for around 700,000 years. Whilst the shallowest permafrost has a vertical extent of below ... landscape. These ongoing transformations are expected to be irreversible for centuries or even millennia. Natural life in the Arctic is affected greatly. As the tundra warms, its soil becomes more hospitable to earthworms and larger plants, and the taiga, boreal forests spread to the north - yet this also makes the landscape more prone to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Climate Change
Present-day climate change includes both global warming—the ongoing increase in Global surface temperature, global average temperature—and its wider effects on Earth's climate system. Climate variability and change, Climate change in a broader sense also includes previous long-term changes to Earth's climate. The current rise in global temperatures is Scientific consensus on climate change, driven by human activities, especially fossil fuel burning since the Industrial Revolution. Fossil fuel use, Deforestation and climate change, deforestation, and some Greenhouse gas emissions from agriculture, agricultural and Environmental impact of concrete, industrial practices release greenhouse gases. These gases greenhouse effect, absorb some of the heat that the Earth Thermal radiation, radiates after it warms from sunlight, warming the lower atmosphere. Carbon dioxide, the primary gas driving global warming, Carbon dioxide in Earth's atmosphere, has increased in concentratio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NOAA Ships And Aircraft
The Office of Marine and Aviation Operations (OMAO) is a division of the National Oceanic and Atmospheric Administration (NOAA) which operates a wide variety of specialized ships and aircraft to carry out the environmental and scientific missions of NOAA. Administration NOAA′s Office of Marine and Aviation Operations (OMAO) operates NOAA′s aircraft and ships. OMAO also manages the NOAA Small Boat Program and the NOAA Diving Program, the latter having as part of its mission the job of ensuring a level of diving skill conducive to safe and efficient operations in NOAA-sponsored underwater activities. A National Oceanic and Atmospheric Administration Commissioned Officer Corps (NOAA Corps) rear admiral serves as both the director of the NOAA Corps and of OMAO. A NOAA Corps rear admiral (lower half) serves as the director of the Marine and Aviation Operations Centers. Manning and resource management NOAA's aircraft and ships are operated and managed by a combination of NOA ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
