A physiologically realistic model has been constructed for a theoretical study of the mechanisms by which the vertebrate visual system absorbs linearly polarized light. Using a 4 x 4 matrix technique, analytic solutions to Maxwell's equations have been deduced for rod and cone photoreceptors, allowing calculation of the absorbance as a function of wavelength for a variety of illumination geomet...

The light-induced absorbance change at 518 nm of isolated chloroplasts consists of a rapid phase, and a slow phase which is complete in about 20 sec. The slow component of the 518 nm absorbance change correlates with the light-induced change in 90 degrees light scattering at 518 nm. Both show a similar time course, similar pH dependence with a maximum at pH 6.0, and similar sensitivity to inhib...

We have developed the first red fluorescent protein, named rsTagRFP, which possesses reversibly photoswitchable absorbance spectra. Illumination with blue and yellow light switches rsTagRFP into a red fluorescent state (ON state) or nonfluorescent state (OFF state), respectively. The ON and OFF states exhibit absorbance maxima at 567 and 440 nm, respectively. Due to the photoswitchable absorban...

The charge separation and excited states of antenna bacteriochlorophyll in membrane fragments of the recently discovered photosynthetic bacterium Heliobacterium chlorum were studied by absorbance-difference spectroscopy. Formation of singlet excited states of bacteriochlorophyll g with a lifetime of 200 ps or less was observed as the disappearance of the ground state absorption bands. From the ...

Zinc sulfide (ZnS) thin films of different thickness were deposited on Corning 7059 glass substrate at room temperature and high vacuum using resistive heating technique. The film properties investigated include their absorbance / transmittance / reflectance spectra, band gap, refractive index, extinction coefficient, optical conductivity, complex dielectric constant and thickness. The films we...

The predictions of the theory of light propagation in weakly absorbing anisotropic minerals are tested against systematic measurements of the infrared absorbance spectra of calcite, olivine, and topaz oriented in both principal and random sections, using both polarized and unpolarized light. We show that if the linear polarized maximum absorbance is smaller than ~0.3, or if the ratio of maximum...

This publication uses a colorimetric method based on the absorbance spectra of dye solutions to improve on Beer’s law when calculating the dye concentrations of a three-component mixture. The performance of the new method is compared with that of Beer’s law evaluated at three wavelengths, and Beer’s law evaluated at 16 wavelengths. Colorimetric method gives the best prediction of d...

The aim of this study was to estimate the concentration of uric acid (UA) optically by using the original and processed ultraviolet (UV) absorbance spectra of spent dialysate. Also, the effect of using several wavelengths (multi-wavelength algorithms) for estimation was examined. This paper gives an overview of seven studies carried out in Linköping, Sweden, and Tallinn, Estonia. A total of 60 ...