Napierian absorbance

The iimnodified temi absorbance usually means this quantity, though some authors use the Napierian absorbance B = -hiT. The absorbance is so iisefiil because it nomially increases linearly with path length, /, tlirough the sample and with the concentration, c, of the absorbing species within the sample. The relationship is usually called Beer s law ... 

Naphthyl)ethyl isocyanate, chiral derivatizing reagent, 6 76t 1-Naphthyl-Al-methylcarbamate, 17 84 Napierian absorbance, 23 126 Naples yellow, 14 792 Napping, of staple-fiber non woven fabrics, 17 515... 

The International Union of Pure and Applied Chemistry recommends that the definition should now be based on the ratio of the radiant power of incident radiation (Pq) to the radiant power of transmitted radiation (P). Thus, A = log(Po/P) = log T. In solution, Pq would refer to the radiant power of light transmitted through the reference sample. T is referred to as the transmittance. If natural logarithms are used, the quantity, symbolized by P, is referred to as the Napierian absorbance. Thus, B = ln(Po/P). The definition assumes that light reflection and light scattering are negligible. If not, the appropriate term for log(Po/P) is attenuance. See Beer-Lambert Law Absorption Coefficient Absorption Spectroscopy... 

In reference [19] the symbol A is used for decadic absorbance, and B for napierian absorbance. 

In the gas phase the (napierian) absorbance At is proportional to the partial pressure p of the absorbing species at a specified reference temperature (usually T=298 K) and to the pathlength I of the radiation absorbing column (Eq. 3-6). 

In the listed matrices the sin, cos, sinh, and cosh functions arise from the exponentiation according to equation (3.2-4). Here, A stands for the Napierian absorbance. 

The product bl may be written as B, which is known as the Napierian absorbance or Napierian extinction ... 

B Napierian absorbance proportionality factor in activity-coefficient expression... 

The term Bouguer-Lambert law is not familiar to many spectroscopists. The term Beer-Lambert law or merely Beer s law is frequently used in its place. Technically, Beer s law refers to the observation that the contribution of an absorber to the absorbance of a sample is proportional to the concentration of the absorber. The symbol k is referred to by some spectroscopists as the Beer-Lambert absorption coejficient. Because of the possibility of decadic or napierian absorbance and the various units by which concentration can be expressed, several different quantities are all Beer-Lambert absorption coefficients. The term absorptivity is commonly used in equations for decadic absorbance and can include concentration in any rmits. The term linear absorption coefficient is the usual name for the linear napierian absorption coefficient of a pure material. 

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