Secondary Emission
Secondary Emission - Related Videos
08:18
Design and Use of a Full Flow Sampling System (FFS) for the Quantification of Methane Emissions
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Cited by 13 •
2016
We have designed, developed, and implemented a novel full flow sampling system (FFS) for quantification of methane emissions and greenhouse gases from across the natural gas supply chain.
02:39
Emission Spectra
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2020
When solids, liquids, or condensed gases are heated sufficiently, they radiate some of the excess energy as light. Photons produced in this manner have a range of energies, and thereby produce a continuous spectrum in which an unbroken series of wavelengths is present. In contrast to continuous spectra, light can also occur as discrete or line spectra having very narrow linewidths interspersed throughout the spectral regions. Exciting a gas at low partial pressure using an electrical current,...
02:47
Metal Flame Emission - Concepts
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2020
Metal Flame Emission Flame testing is an analytical technique where a sample is placed in a flame, and the characteristic flame color is used to identify the substance. Each element has a characteristic light emission when placed into a flame, meaning each element produces a unique color. This phenomenon is used in fireworks displays, where the color of the fireworks corresponds to a specific characteristic of a metal. The emission of colored light from a burning sample is the direct result of...
07:27
Metal Flame Emission - Student Protocol
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2020
Source: Smaa Koraym at Johns Hopkins University, MD, USA Metal Flame Emission TestingExpand In this lab, you will excite the electrons of six metal chloride salts with heat from a flame and measure the wavelength of light emitted by the relaxing electrons. The emitted light is in the visible spectrum, so you will see different colored flames for the different metals. At the end of the lab, you will measure the emission spectrum of a sparkler and use the data you collected from the metal...
10:30
Simultaneously Capturing Real-time Images in Two Emission Channels Using a Dual Camera Emission Splitting System: Applications to Cell Adhesion
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Cited by 4 •
2013
Dual camera emission splitting systems for two-color fluorescence microscopy generate real-time image sequences with exceptional optical and temporal resolution, a requirement of certain live cell assays including parallel plate flow chamber adhesion assays. When software is employed to merge images from simultaneously acquired emission channels, pseudocolored image sequences are produced.
FAQs
Sunlight drives oxidation reactions involving directly released nitrogen oxides and volatile organic compounds. These reactions can generate ozone and peroxyacetyl nitrate, changing the chemical mixture away from the original emissions. Because formation depends on sunlight-driven chemistry, atmospheric conditions can affect when and where these secondary pollutants appear, making air-quality interpretation more complex than measuring source emissions alone.
Condensation transfers transformed substances into atmospheric particles, while neutralization allows acidic and basic compounds to react and form particulate products. Sulfur dioxide can contribute to sulfate aerosols, and ammonia can participate in nitrate aerosol formation. These processes extend secondary emission beyond gas-phase chemistry and help explain changes in airborne particle levels, visibility, and environmental effects.
The composition of the released pollutants strongly influences the products that develop. Nitrogen oxides and volatile organic compounds can participate in reactions producing ozone and peroxyacetyl nitrate, whereas sulfur dioxide and ammonia contribute to sulfate and nitrate aerosols through different transformation pathways. Identifying the starting pollutants therefore helps researchers connect observed atmospheric products with likely emission sources.
Changing environmental conditions can alter pollutant formation and transport after substances leave their sources. Sunlight is especially important because it drives oxidation reactions, while atmospheric transformation, condensation, and neutralization influence whether products remain gaseous or become aerosols. These factors affect where pollutants accumulate, how long their effects persist, and the resulting impacts on air quality and visibility.
Researchers use evidence of transformed pollutants to interpret air-quality measurements and improve emission inventories. Instead of accounting only for substances released directly, they examine how nitrogen oxides, volatile organic compounds, sulfur dioxide, and ammonia contribute to later atmospheric products. This broader accounting supports more complete assessments of pollutant formation, transport, visibility, climate effects, and potential human-health concerns.
Understanding the pathways from precursor pollutants to ozone, peroxyacetyl nitrate, sulfate, and nitrate aerosols helps researchers design pollution-control strategies around the substances that initiate atmospheric transformations. It also supports evaluation of how changing environmental conditions may influence results. This perspective is important because reducing direct releases can affect not only immediate air quality but also later pollutant formation and transport.