Vacuum evaporated crystalline films of Zinc Selenide (ZnSe) have been characterized by using optical spectroscopy (especially transmission and absorption spectra). Thin films of ZnSe have been deposited by vacuum evaporation technique on highly clean glass substrates and their optical properties such as refractive index (n), extinction coefficient (k), and energy band gap have been studied. The...

Membrane osmometry is used to measure osmotic pressures of dilute solutions containing quasi-spherical CdSe nanocrystals covered with polymer brushes in toluene in the range 31 to 45°C. Osmotic-pressure data, as a function of nanocrystal concentration, yield the molecular weight and the osmotic second virial coefficient of the nanocrystals; the latter is related to the potential of mean force b...

A non-invasive method for measuring the refractive index, extinction coefficient and film thickness of absorptive thin films using spectral-domain optical coherent tomography is proposed, analyzed and experimentally demonstrated. Such an optical system employing a normal-incident beam of light exhibits a high spatial resolution. There are no mechanical moving parts involved for the measurement ...

We have observed a core in the northern streamer of the IC5146 cloud using the MPIfR 19-channel Bolometer system on the IRAM 30m telescope at a wavelength of 1.2 mm. We smoothed our observations to the same angular resolution (30) as a new map of the NIR extinction of this cloud (Lada, Alves, and Lada 1998) and in this way obtained direct measurements of the ratio of millimeter emissivity to du...

Question: Can parasites stabilize host-population dynamics and thereby reduce the risk of host extinction? Model: We analysed a discrete-time model of logistic growth in an annual, asexual host population. Infection was assumed to reduce host fecundity, but not host survival. Using simulations, we determined whether parasites stabilized or destabilized host-population dynamics. We calculated th...

An experimental investigation was carried out to determine possible differences in visible light extinction properties of continental and maritime air. Urban, desert, and oceanic atmospheres were probed by means of a stable photodiode radiometer using direct sunlight as the source. No major differences were found for the three locations. Experimental coefficients generally lie slightly below mo...

We found that the extinction coefficient of ion-beam-sputtered titanium dioxide films first decreased with increasing annealing temperature then increased drastically when annealing temperature was increased above ~200 degrees C for 24 h of annealing time. The decreasing extinction coefficient with annealing temperature was attributed to a reduction in absorption owing to oxidation of the film ...

The use of SAGE III multiwavelength aerosol extinction coefficient measurements to infer PSC type is contingent on the robustness of both the extinction magnitude and its spectral variation. Past validation with SAGE II and other similar measurements has shown that the SAGE III extinction coefficient measurements are reliable though the comparisons have been greatly weighted toward measurements...

Widely varying values for the molar extinction coefficient of 2.6-dichlorophenoi indophenol have been reported by various workers 1-9. A possible source of this variation may be the different samples of DCIP used, due either ~o the presence of impurities or to the presence of mixtures of the anhydrous and hydrated forms of DCIP sodium salt. However. failure to realise that DCIP is a weak acid w...