Kenzu Abdella

Learn More
A new second-order turbulence closure scheme is proposed for the oceanic mixed layer. The scheme is similar in complexity to a Mellor–Yamada level 2.5 scheme in that the turbulent kinetic energy is the only turbulence quantity treated prognostically with the others determined diagnostically. The main difference lies in the treatment of the turbulent fluxes.(More)
Color images can be treated as two-dimensional quaternion functions. For analysis of quaternion images, a joint space-wavenumber localized quaternion S transform (QS) is presented in this study for a simultaneous determination of the local color image spectra. The QS transform uses a two-dimensional Gaussian localizing window that scales with wavenumbers.(More)
K e y w o r d s D r o p s in electric fields, Zero gravity, Viscous free surface problems. 1. I N T R O D U C T I O N In th is pape r , we consider a large viscous d rop t ha t is sub jec t ed to an app l ied e lect r ic field in a zero g rav i ty env i ronment . Due to the appl ied electr ic field, an electr ic charge is induced on the surface of the drop(More)
In this paper, an economic epidemiological model with vaccination is studied. The stability of the endemic steady-state is analyzed and some bifurcation properties of the system are investigated. It is established that the system exhibits saddle-point and period-doubling bifurcations when adult susceptible individuals are vaccinated. Furthermore, it is(More)
Presented in this paper is an analytic approximation to the thermal-fluid problem involving mixed convective heat transfer from a rotating isothermal cylinder placed in a non-uniform stream shear flow. The approximation is obtained using a series expansion of the scaled boundary layer equations in terms of an appropriate boundary layer variable. The(More)
In this paper we will establish some identities involving sums of reciprocals<lb>of single binomial coefficients. We will subsume and extend some results obtained by<lb>Sury Wang and Zhao; furthermore we shall give bounds on some resulting series which<lb>depend on several parameters. We then extend the results to obtain identities for sums<lb>of(More)