The recent speculation on the possibility of achieving gigantic enhancement for surface-enhanced Raman scattering at cryogenic substrate temperatures is examined using a simple theoretical model. The surfaceplasmon enhancement mechanism is modeled using the Fermi-electron gas approach instead of the Drude model as used previously in the literature. Due to the diminution of substrate polarizabil...

An approach to identifying climate changes is presented that does not hinge on simulations of natural climate variations or anthropogenic changes. Observed interdecadal climate variations are decomposed into several discriminants, mutually uncorrelated spatiotemporal components with a maximal ratio of interdecadal-to-intradecadal variance. The dominant discriminants of twentieth-century variati...

We analyze the equilibrium spatial distribution of surface temperatures of patterned surfaces. The surface is exposed to a constant external heat flux and has a fixed internal temperature that is coupled to the outside heat fluxes by finite heat conductivity across the surface. It is assumed that the temperatures are sufficiently high so that the thermal wavelength (a few microns at room temper...

In this line of research, Caram de Assis (2002) traces a study on the values of transmission for diverse glass types. The glasses that presented the biggest superficial temperatures, as the term-absorbents, act as “radiators”, decreasing the air temperature in the interior of the prototypes. However, the colorless glass showed that temperature increases less with the sun incidence but the insid...

Radiative feedbacks in the climate system are the primary uncertainty affecting estimates of anthropogenic global warming and climate change (Knutti & Hergerl, 2008; IPCC, 2007). While the feedbacks of most interest are on the long time scales associated with anthropogenic greenhouse gas forcing – decadal or longer – our most accurate satellite measurements of global radiative fluxes are closer...

The effect of physical factors on fish species composition was studied during 12 months inAsa Lake, Nigeria. Fish and water samples were collected bimonthly (March 2003 to February 2004) in the morning. Fish samples were caught with gill nets set at the surface and bottom habitats. There were 11 fish families and 21 species. Osteoglossidae, Anabantidae, Channidae, Schilbedae and Cyprinidae were...

the propose of this paper is to introduce a new model for crude oil fouling in preheat trains of crude distillation unit. the experimental results of australian light crude oil with the tube side surface temperatures between 200-260 oc and fluid velocity ranged 0.25 to 0.4m/s were used. the activation energy of chemical reaction depends on the surface temperature has been calculated.  the model...