Introduction The development of space-borne hyper-spectral IR sounders (AIRS/EOS-Aqua, IASI/MetOp) opens new opportunities for detecting the variations of atmospheric carbon dioxide (CO2) and methane (CH4) concentrations. The capabilities to retrieve atmospheric column-average CO2 mixing ratio and similar column-average CH4 mixing ratio (or CH4 columns) from satellite measurements is of signifi...

One strategy to decrease the amount of oxides of nitrogen formed and emitted from certain combustion devices, such as the internal combustion engine, is to recirculate and introduce a portion of the unburned product gases with the air and fuel. The effect of the re-circulated gases is to decrease the maximum temperatures in the flame zone, and hence decrease NOx formation. However, dilution of ...

Mathematical models and associated numerical techniques have been developed to investigate the complicated transport phenomena in spot hybrid laser-MIG keyhole welding. A continuum formulation is used to handle solid phase, liquid phase, and the mushy zone during the melting and solidification processes. The volume of fluid (VOF) method is employed to handle free surfaces, and the enthalpy meth...

Apollo X ray spectrometer data provide chemical information for 9% of the lunar surface. Galileo solid state imaging system (SSI) multispectral data for the Moon are employed to reexamine the long-accepted positive correlation between lunar surface reflectance (or albedo) and aluminum concentration, derived from Apollo X ray spectrometer data. The overall goal of the analysis is to quantify the...

Stirred tanks and bubble columns are widely used as mixing essels and bioreactors. Average spatial fluid velocity gradients t the level of the eddies or the prevailing shear rate, is an imporant variable in bioreactors but is not easy to characterize. A nowledge of shear rate is essential for at least two main reasons: 1) shear rate influences the average apparent viscosity of nonewtonian fluid...

Anonymous Referee #1 Received and published: 14 June 2007 This paper analyzes the mixing properties of the stratosphere for 1979-2005 using the finite-time Lyapunov exponents computed from the NCEP/NCAR reanalysis winds. The length of the dataset allows the authors to perform a meaningful multiple regression analysis, which includes the climatology, linear trend, QBO, solar cycle, and ENSO. The...

The inversion of helioseismic modes leads to precise constraints on the internal structure of the Sun, which must be satissed by the computed solar models. Including the element segregation which occurred in the Sun since its formation leads to solar models in much better agreement with the inversion structure than those which ignore it. However the observed lithium depletion cannot be explaine...

We consider the effect of a random magnetic field in the convective zone of the Sun on resonant neutrino spin-flavour oscillations. The expected signals in the different experiments (SK,GALLEX-SAGE,Homestake) are obtained as a function of the level of noise, regular magnetic field and neutrino mixing parameters. Previous results obtained for small mixing and ad-hoc regular magnetic profiles are...

Nutrient cycling in Lake Tanganyika is influenced by the tilting of the thermocline (Coulter 1991). Prevailing southeast winds during the four month dry season (May through September) cause the thermocline to rise in the south bringing nutrient rich waters from depth to the surface at the southern end of the lake (Coulter 1991). However, related upwelling events also occur in the north, bringin...

The prediction of pollutant concentrations in the coastal waters is essential for water quality control. The description of physical processes and their implementation in computer models shows that there is neither a “complete model” including all important spatial and temporal scales of the dominant processes nor a standard procedure for the coupling of models. This is explained by deficiencie...