999 resultados para Hydrological stability
Resumo:
The thermal stability of electron beam deposited TiO2 monolayers and TiO2/SiO2 high reflectors (HR) during 300 to 1100 degrees C annealing is studied. It is found that the optical loss of film increases with the increase in annealing temperature, due to the phase change, crystallisation and deoxidising of film. Scattering loss dominates the optical property degradation of film below 900 degrees C, while the absorption is another factor at 1100 degrees C. The increase in refractive index and decrease in physical thickness of TiO2 layer shift the spectra of HR above 900 degrees C. The possible crack mechanism on the surface of HR during annealing is discussed. Guidance for application on high temperature stable optical coatings is given.
Resumo:
The abundance of juvenile blue crabs (Callinectes sapidus) in the northcentral Gulf of Mexico was investigated in response to climate-related hydrological regimes. Two distinct periods of blue crab abundance (1, 1973–94 and 2, 1997–2005) were associated with two opposite climaterelated hydrological regimes. Period 1 was characterized by high numbers of crabs, whereas period 2 was characterized by low numbers of crabs. The cold phase of the Atlantic Multidecadal Oscillation (AMO) and high north-south wind momentum were associated with period 1. Hydrological conditions associated with phases of the AMO and North Atlantic Oscillation (NAO) in conjunction with the north-south wind momentum may favor blue crab productivity by influencing blue crab predation dynamics through the exclusion of predators. About 25% (22–28%) of the variability in blue crab abundance was explained by a north–south wind momentum in concert with either salinity, precipitation, or the Palmer drought severity index, or by a combination of the NAO and precip
Resumo:
This paper investigates the boundedness and convergence properties of two general iterative processes which involve sequences of self-mappings on either complete metric or Banach spaces. The sequences of self-mappings considered in the first iterative scheme are constructed by linear combinations of a set of self-mappings, each of them being a weighted version of a certain primary self-mapping on the same space. The sequences of self-mappings of the second iterative scheme are powers of an iteration-dependent scaled version of the primary self-mapping. Some applications are also given to the important problem of global stability of a class of extended nonlinear polytopic-type parameterizations of certain dynamic systems.