We present a climatological model of the extinction coefficient of stratospheric aerosols in the UV-visible range based on SAGE II data. The model is a function of wavelength, latitude, relative altitude with respect to the tropopause and depends on the volcanism level. The vertical structure describes the tropopause region, the Junge layer and the high altitude domain. The model is shown to pr...

It is well known that for an isolated population, the probability of extinction is positively related to population size variation: more variation is associated with more extinction. What, then, is the relation of extinction to population size variation for a population embedded in a metapopulation and subjected to repeated extinction and recolonization? In this case, the extinction risk can be...

An examination of 2yr of Cloud–Aerosol Lidar Infrared Pathfinder Satellite Observations (CALIPSO) lidar observations and CloudSat cloud radar observations shows that ice clouds at temperatures below about 2458C frequently fall below the CloudSat radar’s detection threshold yet are readily detectable by the lidar. The CALIPSO icewater content (IWC)detection threshold is about 0.1 versus 5mgm for...

Coupled nonlinear Schrödinger (CNLS) equations for the fiber couplers with asymmetric selfphase modulation (SPM) and cross-phase modulation (XPM) are studied. With symbolic computation, oneand two-soliton solutions are obtained for the constantand variable-coefficient CNLS equations. Switching dynamics of the solitons is discussed, and effects of the second-order group-velocity dispersion β2, S...

Thin films of tin sulfide/cadmium sulfide (SnS/CdS) were prepared bythermal evaporation method at room temperature on a glass substrate and then annealedat different temperature with the aim of optimizing the optical properties of the materialfor use in photovoltaic solar cell devices. The effect of annealing on optical propertiesof SnS/CdS film was studied in the temper...

In our quest to develop good materials as photosensitizers for photovoltaic dye-sensitized solar cells (DSSCs), cis-dithiocyanato-4-(2,3-dimethylacrylic acid)-2,2'-bipyridyl-4-(9-anthracenyl-(2,3-dimethylacrylic)-2,2'-bipyridyl ruthenium(II) complex, a high molar extinction coefficient charge transfer sensitizer, was designed, synthesized and characterized by spectroscopy and electrochemical te...

In this research, Germanium-carbon coatings were deposited on ZnS substrates by plasma enhanced chemical vapor deposition (PECVD) using GeH4 and CH4 precursors. Optical parameters of the Ge1-xCx coating such as refractive index, Absorption coefficient, extinction coefficient and band gap were measured by the Swanepoel method based on the transmittance spectrum. The results showed that the refra...