Absorption range

Germane is used, along with silane, SiH, to make amorphous or crystalline siUcon solar cells having an extended solar energy absorption range to increase conversion efficiency. 

A with a max at 3800A. The absorption overlap of the nitrocompds is plainly evident. The position and slope of each curve in Fig 1 can be qualitatively correlated with the absorption range and % transmittance at the peak for each compd. Nitro me thane, which absorbs more at shorter wave lengths and exhibits the least overlap of the toluene-PPO emission spectrum, accordingly has the least effect on the count Tate of the pure scintiliator... 

Getting more creative with the chemistry, a chemist can add other desirable features to these molecules. Adding long chains of hydrocarbons can help it mix better with suntan oils to spread more easily on the skin. The resonance bonds can be modified a little bit to get a broader absorption range, expanding into the longer wave UV-A region. 

There has been some interest in extending the absorption range of cyanine dyes to longer wavelengths into the near-infrared region of the spectrum. Consideration of the spectral data for thiazole derivatives 118-120 is of some interest in this respect. Cyanine dye 118 shows the characteristic visible absorption spectrum for a dye of this type, giving a... 

Phototactic action spectra of Phormidium autumnale and Phormidium uncinatum, measured by Nultsch86>89), show prominent maxima in the absorption range of C-phycoerythrin and smaller, but distinct, peaks in the absorption range of C-phyco-cyanin. Red light absorbed by chlorophyll a is not active, while in the blue range absorbedby the Soret band, the action spectrum shows aminimum(Fig. 6). Nultsch87) concluded that biliproteins are photoreceptors of phototaxis, but independently of the photosynthetic electron transport and phosphorylation. 

Type of Compound Infrared Absorption due to Following Functional Groups Absorption Range (cm-1) Mass Spectra m/z Signal... 

This chapter shows that zeolite L is a very suitable host for the arrangement of a wide variety of chromophores. The structure of zeolite L is such that the formation of non-fluorescent dimers inside the channels can be prohibited and chromophores can be aligned in a certain direction. We have shown that this host-guest system can be used to make very efficient nanoscale two-directional photonic antenna systems. A broad spectral absorption range can be achieved by using several different cationic and neutral dyes. 

Knowledge of drug properties, especially solubility in surfactants or as a function of pH, is essential. One could anticipate precipitation of the drug as the pH changes in solution, or if release from the dosage form leads to supersaturation of the test media. Be aware that preparation of a standard solution may be more difficult than expected. It is customary to use a small amount of alcohol to dissolve the standard completely. A history of the typical absorptivity range of the standard can be very useful to determine if the standard has been prepared properly. 

Even more elegantly, the local resolution is improved by irradiation with very intense focused femtosecond laser pulses outside the absorption range of the fluoro-phore (e.g., in the near-infrared). The very intense focus of the laser beam—and only this—will excite the fluorophore by nonresonant two-photon absorption. Artifacts by scattered primary radiation are ruled out and the local resolution is comparable to a confocal microscope. In addition, the damage of the sample by laser light absorption is reduced to a minimum. 

In water, A-nitrosodimethylamine reacts with OH radicals via abstraction of the hydrogen atom on the methyl group. The rate constant for this reaction is 4.30 x 10 /M-sec. No significant intermediate compounds were identified in the absorption range 250-800 nm (Mezyk et al., 2004). 

Percutaneous penetration of 7V-nitrosodiethanolamine was measured using cryo-preserved human trunk skin and three vehicle formulations (isopropyl myristate, sunscreen cream or a 10% shampoo) containing 7V-nitroso[ C]diethanolamine. The absorption rate of a low dermal dose (10 ixg/cm ) of 7V-nitrosodiethanolamine was a linear function of the concentration (0.06, 0.2 or 0.6 Xg/ xL) applied to the skin. The peak rates for the isopropyl m uistate and shampoo vehicles were seen within five hours and for the sunscreen somewhat later. Total 48-h absorption ranged from 35 to 65% of the dose and was formulation-dependent (isopropyl m uistate > shampoo > sunscreen). A total absorption of 4-6 x JcaE was estimated to equate to an applied N-nitrosodiethanolamine dose of 10 x%lcaE. When applied as a large infinite dose (0.5 mg/cm ), total 7V-nitrosodiethanolamine absorption (4-35% of the applied dose) followed a different rank order (shampoo > isopropyl m uistate > sunscreen), probably due to the barrier-damaging properties of the vehicles. The permeability coefficient for isopropyl myristate was 3.5 X 10 cm/h (Franz etal., 1993). 

The absorption ranges of the various types of alcohols appear in Table 3.2, below. These values are for neat samples of the alcohols. 

The carbonyl frequency of tertiary amides is independent of the physical state since hydrogen bonding with another tertiary amide group is impossible. The C=0 absorption occurs in the range of 1680-1630 cm-1. The absorption range of tertiary amides in solution is influenced by hydrogen bonding with the solvent N, V-Diethylacetamide absorbs at 1647 cm-1 in di-oxane and at 1615 cm-1 in methanol. 

The frequencies of interest for studies of collision-induced absorption range from microwave frequencies to the ultraviolet, depending on the systems and specific transitions considered. Light sources, monochromators, detectors and pressure cells are needed for such studies, which are more or less the same as in the conventional spectroscopies. 

The logarithmic relation of P0/P to concentration arises because, in each infinitesimal portion of the total volume, the decrease in power is proportional to the power incident upon that section. As light travels through the sample, the power loss in each succeeding layer decreases, because the magnitude of the incident power that reaches each layer is decreasing. Molar absorptivity ranges from 0 (if the probability for photon absorption is 0) to approximately 105 M-1 cm-1 (when the probability for photon absorption approaches unity). 

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