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The best spectral bandwidth achievable is a specification of the UV spectrophotometer, and it characterizes how monochromatic the incident light can be. If this bandwidth is comparable to (or more than) the width of the absorption peak of the sample component, then the measured extinction coefficient will not be accurate.
Photolysis occurs in the atmosphere as part of a series of reactions by which primary pollutants such as hydrocarbons and nitrogen oxides react to form secondary pollutants such as peroxyacyl nitrates. See Photochemical smog. The two most important photodissociation reactions in the troposphere are firstly:
Photoexcitation is the first step in a photochemical process where the reactant is elevated to a state of higher energy, an excited state.The first law of photochemistry, known as the Grotthuss–Draper law (for chemists Theodor Grotthuss and John W. Draper), states that light must be absorbed by a chemical substance in order for a photochemical reaction to take place.
The specificity of absorption spectra allows compounds to be distinguished from one another in a mixture, making absorption spectroscopy useful in wide variety of applications. For instance, Infrared gas analyzers can be used to identify the presence of pollutants in the air, distinguishing the pollutant from nitrogen, oxygen, water, and other ...
Nitrogen assimilation is the formation of organic nitrogen compounds like amino acids from inorganic nitrogen compounds present in the environment. Organisms like plants, fungi and certain bacteria that can fix nitrogen gas (N 2) depend on the ability to assimilate nitrate or ammonia for their needs. Other organisms, like animals, depend ...
Intrinsic DNA fluorescence is the fluorescence emitted directly by DNA when it absorbs ultraviolet (UV) radiation. It contrasts to that stemming from fluorescent labels that are either simply bound to DNA or covalently attached to it, [1] [2] widely used in biological applications; such labels may be chemically modified, not naturally occurring, nucleobases.
To derive SUVA, first, UVC light (UV spectrum subtypes) at 254 nm or 280 nm, [2] is measured in units of absorbance per meter of path length, often the sample must be diluted with ultrapure water because absorbance can be high. [3]
Diffuse reflectance spectroscopy, or diffuse reflection spectroscopy, is a subset of absorption spectroscopy.It is sometimes called remission spectroscopy.Remission is the reflection or back-scattering of light by a material, while transmission is the passage of light through a material.