We study the relation between out-of-equilibrium (hysteretic) and equilibrium behavior in the capillary condensation of Ñuids in disordered mesoporous solids. Using mean-Ðeld density functional theory, we show that a simple lattice-gas model can reproduce the major experimental observations and that the classical van der Waals picture of metastability fails due the appearance of many metastable...

This work reports on a study of the biosorption of copper and cobalt, both singly and in combination (in equimolar concentrations), by the resting cells of Penicillium brevicompactum. Equilibrium batch sorption studies were carried out at 30 degrees C and pH 5.0 for a contact time of 1 hour to guarantee that equilibrium was reached. The equilibrium data were analyzed using the Langmuir and Freu...

This paper presents and develops a novel methodology to determine thermodynamic parameters of binary gas co-adsorption equilibria at given total pressure, based exclusively on binary gravimetric measurements at this same total pressure, together with single component isotherms. By “Incremental Gravimetry”, we designate a procedure in which the adsorbent sample is submitted to increments of comp...

in this study, the potential of biosorbent obtained from silk maze, was investigated for the batch biosorption of direct red 81 (dr 81) in aqueous solution. the effects of temperature, biosorbent amount, contact time, initial dye concentration and ultrasonic irradiation were also evaluated. furthermore, experimental equilibrium and kinetics data were fitted by langmuir and freundlich isotherms ...

Coliphages T1 and T7 of Escherichia coli were absorbed by kaolinite (K) and montmorillonite (M). Maximum adsorption of T7 (96%) to M was greater than that of T1 (84%), but the adsorption of both coliphages to K was the same (99%). Positively charged sites (i.e., anion exchange sites) on the clays appeared to be primarily responsible for the adsorption of T1 to K but only partially responsible f...

Uncommon methods of formation and analysis of lipid monolayers have enabled the recognition of several monolayer states and the identification of that in which molecular organization corresponds closely to that of the bilayer. Monolayers were formed by continuously adding a solution of phospholipid [dimyristoyl phosphatidylcholine in hexane/ethanol, 9:1 (vol/vol)] to the air/water interface of ...

The aim of this work was to obtain information about interactions between polyphenols and β-glucan through linear adsorption equilibrium models. Polyphenolic compounds can interact with various food ingredients such as carbohydrates, proteins and lipids and these interactions can affect polyphenol bioactivities. Interactions can be studied through the adsorption process at a constant temperatur...

Metal detoxification of waste water and industrial effluents are of increasing importance to industrialization in the twenty first century. The ability of coconut (cocos nucifera L) coir dust (CD), carbohydrate toluenediisocyanate resin (CTR) and sulphonated toluenediisocyanate resin (STR) to remove Pb(II) ions from aqueous solution by ion exchange was studied. Percentage ion exchange efficienc...

Unsteady natural convection and heat transfer in a square cavity partially filled with porous media using a thermal non-equilibrium model is studied in this paper. The left vertical wall is maintained at a constant hot temperature Th and the right vertical wall is maintained at a constant cold temperature Tc, while the horizontal walls are adiabatic. The governing equations are obtained by appl...

Two samples of hydroxyl-terminated polydimethylsiloxane having molecular weights the order of 2 X 10 and I X 10 gmol1 were separated into a total of six fractions of relatively narrow molecular weight distribution. Portions of one of the unfractionated polymers and each of the fractions were cross-linked by reacting the hydroxyl chain ends, in the undiluted state, with a tetrafunctional orthosi...