Some Mathematical Aspects of Spread and Stability of Time-Delay Gonorrhea

A mathematical model of time-delay gonorrhea among hetero and homosexuals is presented as a system of first order ordinary coupled integro-differential equations with delayed arguments. A theorem on the positivity of the solutions is proved to establish the feasibility of the proposed mode. Further, the only possible diseased equilibrium state has been identified and the stability analysis of such a state for some epidemiological possibilities has been carried out. It has been observed that the impulsive type inflow of infectives into the population maintained the stability of the diseased equilibrium state and is valid even for the exponential type inflows. In contrast to this, instability sets in when one or other of infective inflows is of the gate type

Couette Flow of a Dusty Incompressible Fluid with One of the Horizontal Moving Boundaries Suddenly Stopped

The unsteady flow of an incompressible viscous fluid with a uniform distribution of dust particles between two parallel plates when one of which is impulsively stopped from the state of uniform motion is studied. Analytical expressions for velocities of the fluid and dust particles have been obtained. It is found that the dust particles slip on the wall which is brought to rest impulsively instead of sticking to it; on the other hand, they stick to the stationary plate. The slip-velocity of the dust is noticed to be decreasing as the physical time increases and the relaxation time of the dust particles decrease

Enhanced photocatalytic activity of mesoporous nano titania decorated with zinc phthalocyanine

Zinc (II) phthalocyanine(Znpc) decorated mesoporous titania (Znpc-TiO2), visible light active nanocatalyst with a specific surface area of 247 m2.g-1 has been synthesized by a hydrothermal method, while undoped TiO2 was UV active. The Znpc-TiO2 degrades one of the highly toxic chemical warfare agents, sulfur mustard (SM), and malchite green dye (MG) photocatalytically in the sunlight with an exposure time of as low as 60 min