2,4,7,9-Tetramethyl-5-decyne-4,7-diol (TMDD) is a non-ionic surfactant which is preferentially used as defoamer in paints and printing ink and for the treatment of surfaces. Effluents of wastewater treatment plants (WWTPs) have been identified as the domination point sources for TMDD in rivers since the removal rate of the compound in the WWTPs is in general less than 70%. However, the dominati...

The simulation of incompressible flows in heterogenous media is an interesting topic with many applications: considering the particular case of free fluids which can filtrate through porous media, we recall for example the hydrological environmental applications and mass transfer in biomechanics. The Stokes/Darcy coupled system provides a linear model to describe such phenomena. We consider a b...

time-delays are important components of many dynamical systems that describe coupling or interconnection between dynamics, propagation or transport phenomena, and heredity and competition in population dynamics. the stabilization with time delay in observation or control represents difficult mathematical challenges in the control of distributed parameter systems. it is well-known that the stabi...

Heat and mass transfer phenomena in annular liquid jets are analyzed at high Reynolds numbers by means of a model derived from the governing equations that takes into account the e€ects of surface tension and boundary conditions at the gas± liquid interfaces and the large di€erences between the thermal and mass di€usivities, densities, dynamic viscosities, and thermal conductivities between gas...

A study of 16 streams in eastern North America shows that riparian deforestation causes channel narrowing, which reduces the total amount of stream habitat and ecosystem per unit channel length and compromises in-stream processing of pollutants. Wide forest reaches had more macroinvertebrates, total ecosystem processing of organic matter, and nitrogen uptake per unit channel length than contigu...

it is well known that the parabolic partial differential equationsin two or more space dimensions with overspecified boundary data,feature in the mathematical modeling of many phenomena. in thisarticle, an inverse problem of determining an unknowntime-dependent source term of a parabolic equation in generaldimensions is considered. employing some transformations, wechange the inverse problem to...

Continuous development and increase of population in the urban areas, a series of problems related to environment such as deforestation, release of toxic materials, solid waste disposals, air pollution and many more, have attracted attention much greater than ever before. The problem of air pollution in cities has become so severe that there is a need for timely information about changes in the...

the heat and mass transfer analysis for mhd casson fluid boundary layer flow over a permeable stretching sheet through a porous medium is carried out. the effect of non-uniform heat generation/absorption and chemical reaction are considered in heat and mass transport equations correspondingly. the heat transfer analysis has been carried out for two different heating processes namely; the prescr...