Wavelength ultraviolet

Ultraviolet wavelengths of 290-310 nm from the UV-B band of radiation constitute the principal tissue-damaging rays of the sun, which are not fully atmospherically filtered. An hour s exposure to the summer sun and its damaging rays can produce a painful burn with a characteristic erythema. The skin has natural mechanisms to prevent or minimize such sun-induced trauma, but it takes time to set these into place. Upon... 

An important observation was that the emission lines are not confined to the narrow visible region of the electromagnetic spectrum. Instrumental detection showed that discrete lines are also present in the infrared and ultraviolet wavelengths, and eventually it showed this in the X-ray region also. It became clear that the wavelength of the line simply corresponded to the energy... 

There are a number of different processes, which may generate optical absorption in the visible and ultraviolet wavelength range. The following transitions are of primary importance for minerals (Platonov 1979 Rossman 1988) ... 

Munakata, N. Hieda, K. Kobayashi, K. Ito, A. Ito, T. Action spectra in ultraviolet wavelengths (150-250 nm) for inactivation and mutagenesis of Bacillus subtilis spores obtained with synchrotron radiation. Photochem. Photobiol. 1986, 44 (3), 385-390. 

Munakata, N. Saito, M. Hieda, K. Inactivation action spectra of Bacillus subtilis spores in extended ultraviolet wavelengths (50-300 nm) obtained with synchrotron radiation. Photo-chem. Photobiol. 1991, 54 (5), 761-768. 

Gorton, H.L. and Vogelmann, T.C., Effects of epidermal cell shape and pigmentation on optical properties of Antirrhinum petals at visible and ultraviolet wavelengths, Plant Physiol, 112, 879, 1996. 

Gallium nitride (GaN) has a hexagonal structure of wurtzite type with a wide direct bandgap of 3.4 eV at 300 K. GaN-based III—V nitrides with wide band gaps are the potential candidates for device applications in the blue and ultraviolet wavelengths... 

Ozone (formula O3) An allotropic form of oxygen, produced by the action of electric discharges or of a certain ultraviolet wavelength of light on oxygen. It is a gas with a characteristic odor, and is a powerful oxidizing agent. 

TABLE 2. Light Transparency in Vacuum Ultraviolet Wavelength Region for Selected Florinated Norbomane Polymers... 

The London force is also often called the dispersion force. The word dispersion here has nothing to do with the role of the London force in colloidal dispersions, but is the result of the role this type of interaction force plays in the dispersion of light in the visible and ultraviolet wavelengths. 

Nowell L H, Hoignd J (1992) Photolysis of Aqueous Chlorine at Sunlight and Ultraviolet Wavelength - I Degradation Rates, Water Research 26 593-598. 

Justus C.G. and B.B. Murphey, Temporal trends in surface irradiance at ultraviolet wavelengths, J. Geophys. Res., 99,1389-1394, 1994... 

Dark Stability. The examples cited have demonstrated that dye sensitized photopolymerization is potentially rapid in solution, but that substantial speed losses result when polymeric binder compositions are used in an imaging fashion. Our work has shown that TBBS activated compositions sensitized by MB can exhibit absolute photospeeds to red light that are comparable to those of commerical photopolymer systems that are sensitive only to ultraviolet wavelengths (65). These systems can offer features not now available in UV-only sensitive systems. The major failure of all such systems, however, is a pronounced lack of stability on dark storage for the lengths of time required by industry standards. 

This system also needs rather short ultraviolet wavelengths for excitation but has the benefit of a time-delayed emission that allows time-gating to block out autofluorescence from the matrix. PET appears to be at work here too. 

High sensitivity detection of non chromophoric organic ions can be achieved by combining the power of suppressed conductivity detection with these columns. Suppressed conductivity is usually a superior approach to using refractive index or low-ultraviolet-wavelength detection. 

The analytical procedure is outlined in Fig. 4.6. Reproducible retention times (which varied less than 2% over a nine-month period) eliminated the need for column reequilibrium. Although some coeluting PAHs (eg anthracene and phenanthrene) had been placed into different fractions, it was clear that no single ultraviolet wavelength was capable of resolving all of the PAHs within a fraction. The sensitivities of the ultraviolet detectors, defined as a signal-to-noise ration of 2, ranged from 0.25 to lng IT1. 

Rhodonine(l 1), Ultraviolet wavelength chromophores Retinal, 11-hydroxy-, ion(l-)... 

Acyl nitrenes are highly reactive but unfortunately their precursors, acyl azides, are chemically reactive, e.g. they acylate amino groups. While sulfonyl- and alkoxycarbonyl azides are somewhat less reactive than acyla-zides, and the nitrenes derived from them are highly reactive (Lwowski, 1970 and for sulfonyl nitrenes see Abramovitch et al., 1981 and references therein), the azides must be irradiated in the UV, below 300 nm. Phos-phorylnitrenes are the most reactive nitrenes known and will insert into CH bonds in the presence of hydroxyl groups (Breslow et al., 1974). Again, photolysis occurs at ultraviolet wavelengths. 

Protein has a secondary structure a-helix, -structure or random chain. The contents of these components in the protein structure can be calculated on the basis of circular dichroism spectrum in the region of far-ultraviolet wavelength (around 220 nm),46 or amino acid sequences.47 Although these methods do not always reflect a secondary structure of protein, they are applicable to research on the structure of proteins, especially homologous proteins whose three-dimensional structures have not been shown. 

Similar studies34 with ethane as a feed led to yields of CH3CHO of 11 i mol/hr, 3 p mol/hr HCHO, and 5 p mol/hr CO2 on irradiation and no products again without irradiation. Data for ZnO itself showed higher selectivities to CH3CHO for unirradiated catalysts than for irradiated catalysts. Photochemical and thermal pathways are clearly different for these materials. A 200 W Hg arc lamp with broad band ultraviolet wavelengths was used for excitation. 

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