Electronic absorption, florescence excitation and AFM studies of selected homogeneous solutions and thin films of mesotetrakis (parahydroxyphenyl) porphyrin (THPP) (1), mesotetrakis (2, 3- dihydroxyphenyl) porphyrin 2, 3-OHPP) (2), mesotetrakis (3, 4-dihydroxyphenyl) porphyrin (3, 4-OHPP) (3) as well as Zn(II) derivative of 2, 3-OHPP (4) under UV lamp and green laser irradiation (532 nm) are ac...

In the retina of dusk-active European cockchafers, Melolontha melolontha, the linear polarization of downwelling light (skylight or light from the tree canopy) is detected by photoreceptors in upward-pointing ommatidia with maximal sensitivity at 520 nm in the green portion of the spectrum. To date no attempt has been made to answer the question of why these beetles detect polarization in the g...

We report 32% efficient frequency doubling of single-frequency 1029 nm light to green light at 514.5 nm using a single-pass configuration. A congruent composition, periodically poled magnesium-doped lithium niobate (PPMgLN) crystal of 50 mm length was used to generate a second-harmonic power of 2.3 W. To our knowledge, this is the highest reported power and efficiency achieved in the second-har...

High-light leaves of the evergreen herb Galax urceolata exhibit a striking color change from green to red during winter months due to anthocyanin synthesis in outermost mesophyll cells. Here we investigate three possible functions of this color change. To test the hypothesis that anthocyanins function as light attenuators, maximum photosystem II efficiency (F(v)/F(m)) of red and green leaves wa...

Measles and canine distemper viruses were grown together in a Vero monkey kidney cell line. Each virus could be identified and individually titrated by using the color contrast produced by the reddish tetra-methyl rhodamine isothiocyanate-tagged antimeasles conjugate and the green fluorescein isothiocyanate-tagged antidistemper conjugate. Both blue light and green light were used for the excita...

Behavioural tests of the magnetic compass of birds and corresponding immunohistological studies on the activation of retinal cryptochrome 1a, the putative receptor molecule, showed oriented behaviour and activated Cry1a under 373 nm UV, 424 nm blue, 502 nm turquoise and 565 nm green light, although the last wavelength does not allow the first step of photoreduction of cryptochrome to the semiqu...

Although there has been significant interest in the develop ment of environmentally friendly pyrotechnics, the develop ment of cost effective barium free green light emitting pyro technic formulations has remained elusive. Many barium compounds are human health hazards, and recent work by Steinhauser has shown that barium ores as raw materials may contain radioactive radium. Recent papers by Kl...

The photocatalytic degradation of the chemical dye AZO and dye effluents in different time duration has been investigated using biologically synthesized silver nanoparticles. Dye industry effluents and AZO dye undergo degradation to form harmless intermediate and colourless products following irradiation by UV and solar light in the presence of green synthesized silver nanoparticles. The degree...

High-brightness blue and green light-emitting diodes ~LEDs! based on II–VI double heterostructures ~DHs! have been successfully grown by molecular-beam epitaxy ~MBE! on ~100! ZnSe substrates. These LED structures consist of a 500–1000 Å thick active region of undoped blue-emitting Zn0.9Cd0.1Se/ZnSe multiple quantum wells or a green-emitting ZnTe0.1Se0.9 single quantum well sandwiched between a ...

Many observers have reported observations of green light emanating from severe thunderstorms in the midwestern United States. Spectral measurements have demonstrated that the dominant wavelength of the light is in the green portion of the visible spectrum and that this is not just a subjective impression. According to the theory proposed by Bohren and Fraser [Bull. Am. Meteorol. Soc. 74, 2185 (...