Radiant power

Radiant power incident on Po Rydberg, unit of energy Ry... 

Mass Absorption Coefficients. Radiation traversing a layer of substance is diminished in intensity by a constant fraction per centimeter thickness x of material. The emergent radiant power P, in terms of incident radiant power Pq, is given by... 

Laws of Photometry. The time rate at which energy is transported in a beam of radiant energy is denoted by the symbol To for the incident beam, and by P for the quantity remaining unabsorbed after passage through a sample or container. The ratio of radiant power transmitted by the sample to the radiant power incident on the sample is the transmittance T ... 

The ratio of the radiant power passing through a sample to that from the radiation s source (T). 

Radiant power boilers are two-phase boilers. Designs typically employ only one drum for the largest installations, whereas smaller power boiler designs generally incorporate two drums. Fossil fuel-fed, radiant power boilers are probably the most common type of equipment employed for large-scale utility power generation. 

The concentration of atoms in the excited state is measured by monitoring their spectral deactivation to the ground state. The radiant power of this mechanism of deactivation is given by ... 

AAS measures the discrete radiation absorbed when ground state atoms are excited to higher energy levels by the absorption of a photon of energy. The radiant power of the absorbed radiation is related to the absorption coefficient of the ground state atoms using the... 

AFS quantifies the discrete radiation emitted by excited state atoms that have been excited by radiation from a spectral source. There are a number of mechanisms that are responsible for the atomic fluorescence signal resonance fluorescence, step-wise fluorescence, direct-line fluorescence, and sensitized fluorescence. Generally, the lowest resonance transition (l->0) is used for AFS. If a line source is used for excitation and if the atomic vapor is dilute, then the radiant power of the atomic... 

On the basis of this equation it can be seen that the radiant power of atomic fluorescence signal is directly proportional to the concentration of the ground state atoms and to the radiant power of the exciting radiation. Therefore, increasing the intensity of the incident beam will improve the sensitivity of the technique. 

In other words, the radiant power of the unabsorbed light decreases exponentially as the thickness of the... 

Second Law Bernard s (1852) or Beer s (1852) Law defines that— the radiant power of a beam of parallel monochromatic radiation decreases in a similar manner as the concentration of the light-absorbing constituent increases . Thus we have ... 

The radiant power of a beam is designated by its intensity of radiation, which in turn is directly proportional to the number of photons per second that are propagated in the beam. 

The procedure may start with the reference experiment, which, in the case under analysis, involved a solution of ferrocene in cyclohexane (ferrocene is a nonphotoreactive substance that converts all the absorbed 366 nm radiation into heat). With the shutter closed, the calorimeter was calibrated using the Joule effect, as described in chapter 8, yielding the calibration constant s. The same solution was then irradiated for a given period of time t (typically, 2-3 min), by opening the shutter. The heat released during this period (g0, determined from the temperature against time plot and from the calibration constant (see chapter 8), leads to the radiant power (radiant energy per second) absorbed by the solution, P = /t. ... 

The main experiment followed a similar procedure. The Joule calibration yields e. The cyclohexane solution of Cr(CO)6 and piperidine was irradiated for a period t. The heat released (Q) provided A0bs H via equation 10.5. If/ / t, then Q derived from the reference experiment needs to be multiplied by t/t. Alternatively, we can simply derive the rate of temperature increase during the irradiation. This rate multiplied by e is equal to rate of heat production (Q/t), which Adamson and co-workers called F. The difference between the radiant power (P) and F gives A0bsH/t. 

The term intensity is commonly used but is imprecise. According to IUPAC recommendations (see Pure 6[ Appl. Chem. 68, 2223-2286 (1996)), this term should be replaced by the spectral radiant power Ph i.e. the radiant power at wavelength X per unit wavelength... 

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