Intensity absorbed

In the preceding formula, denotes the intensity absorbed from the excitation radiation (intensity /g). This absorbed intensity generates fluorescent radiation and other reactions. 

The term fluorescence is used for a transformation of absorbed light into a light (7p) of lower energy. The extent of this transformation is described by the quantum yield factor q. Light intensity absorbed by the sample can be calculated from the light intensity reflected from the clean plate snrfaee (Jq) minus the light intensity (J) reflected from a sample spot [13]. 

Type I copper enzymes are called blue proteins because of their intense absorbance (s 3000 M-1 cm- ) in the electronic absorption spectrum around... 

The minimal quantity of Ru(bpy)3 + that could be detected was determined via fluorescence = 286 nm = 594 nm. The concentration of was determined via UV absorbance (258 nm). The minimal quantity of rhodamine B that could be detected was determined via its extremely intense absorbance at 555 mn. The concentration of anibnium was determined via absorbance (254 mn). 

During the last two or three decades, chemists became used to the application of computers to control their instruments, develop analytical methods, analyse data and, consequently, to apply different statistical methods to explore multivariate correlations between one or more output(s) (e.g. concentration of an analyte) and a set of input variables (e.g. atomic intensities, absorbances). 

The significance of light absorption in biochemical studies lies in the great sensitivity of electronic energy levels of molecules to their immediate environment and to the fact that spectrophotometers are precise and sensitive. The related measurements of circular dichroism and fluorescence also have widespread utility for study of proteins, nucleic acids, coenzymes, and many other biochemical substances that contain intensely absorbing groups or chromophores.58... 

The patent and open literature were searched for examples of dye sensitized photopolymerization in which a common monomer (acrylamide), and one of several common dyes (thionine, T methylene blue, MB or rose bengal, RB) were used in combination with a stated concentration of an activator. The polymerization conditions (monomer concentration, light intensity absorbed, and extent conversion) were stated in each case chosen for inclusion. The relative photospeed of the system was calculated based on several corrections to the raw data. We here define the relative photospeed of a composition as the inverse of the exposure time t needed to effect some fixed percentage of monomer conversion. 

This was true in the above study, where the antisymmetric MC and MCI bands were almost undetectable in some cases, and in order to carry out a complete vibrational analysis it would also be desirable to obtain the infrared spectrum. It has been pointed out that this is difficult using transmission techniques because oxides are such strong IR absorbers at low frequency. However, the extraction of weak signals which are superimposed on an intensely absorbing background can sometimes be realized using a highly sensitive dispersive or Fourier transform spectrometer. 

As in the case of the 1,4-naphthoquinones, there has been considerable interest in developing near-infrared dyes of this class. The dye 22 [100012-51-9] is essentially the 1,5-quinone analogue of 16 (X = S) and shows a long-wavelength peak at 750 nm in trichloromethane (cmax 32000 L mol 1 cm ) [30], Thus, although 22 has the same molecular mass as 16 (X = S), it is both more bathochro-mic and more intensely absorbing. 

In a photochemical reaction with a complex mechanism, the local rate of change of the reactant or product concentrations might have a nonlinear dependence on the light intensity absorbed locally. For example, the rate to be used in Equation 6.19 can be dependent on the nth power of the light intensity. 

Inserting the expression of the average intensity absorbed at / (Equation 6.20) in Equation 6.23, one obtains the local rate (Equation 6.24) and the measured rate (Equation 6.25) of the photochemical reaction. 

For the generation of the FTIR-TPD profiles (A vs. T), the decrease in the intensity (absorbance) of one of the selected bands was monitored, during heating at a constant rate [97]... 

Bicinchoninic Acid (BCA) Assay. The bicin-choninic acid assay for proteins is based on the same reactions as the Folin-Ciocalteau assay. Proteins are again reacted with alkaline cupric ions to form the biuret complex, and these ions are reduced to cuprous ions by the aromatic amino acids in the proteins. In this case, however, the Cu1+ ions form a complex with bicinchoninic acid (Fig. II-6), which has an intense absorbance maximum at 562 nm. This assay shows the same variation from protein to protein as the Folin-Ciocalteau assay, but is more convenient experimentally and can be made somewhat more sensitive. 

The infrared spectrum of the starting alcohol shows a broad absorption at 3400-3640 cm 1 due to an O-H stretch. The alkene product exhibits medium intensity absorbances at 1645-1670 cm-1 and at 3000-3100 cm-1. Monitoring the disappearance of the alcohol absorption makes it possible to decide when reaction is complete. It is also possible to monitor the appearance of the alkene absorptions. 

Third, the hazards of handling and disposing of radioisotopes have made it desirable to find alternative methods of assay. When the assay involves fluorescent or intensely absorbing substrates or products, the sensitivity of HPLC-based assays rivals that of radiochemical assays. 

Second, the absorbance capacity of a compound depends on its molecular structure. Certain compounds, such as carbon dioxide absorb strongly in the mid-IR, whereas other compounds, even those of substantial molecular complexity, have less intensive absorbance. 

The primary negative peaks in the difference spectra of the vest yams have low absorbance values and are seen at 931 cm 1072 cm 1422 cm 1440 cm 1506 cm 1560 cm , 1588 cm" 1657 cm" and 3400 cm". The officer s vest yam contains negative peaks with the highest intensity (absorbance), followed by the archive vest and the new vest, in decreasing order of intensity. This rank order in peak absorbance tracks the same rank order of tensile strength loss reported earlier. 

The fact that the absorption coefficient depends on the wavelength critically affects the determination of the amount of intensity absorbed. In addition, Lambert-Beer s law is limited to dilute solutions. In Eq. (3) only the absorption of the reactant A is considered. However, the decrease in intensity is caused by all light-absorbing components in the solution. For this reason, the amount of light absorbed by all reactants in the solution is given by... 

In 1930, Bowen and Tietz briefly studied the photochemical oxidation of ethanal by oxygen dissolved in hexane or acetic acid solutions at atmospheric pressure and room temperature. The rate of photooxidation is essentially proportional to the square root of the light intensity absorbed and to the concentration of aldehyde. The reaction is inhibited by ethanol. 

The rate, V, of the reaction is proportional to the square root of the light intensity absorbed, h ... 

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