Dynamics of Thermocapillary-Driven Motion of Liquid Drops.

The thermocapillary migration of a drop placed on a solid plate is examined. The Brochard model using the lubrication approximation provides both Marangoni and Poiseuille flow components. The present 2D model extends Brochard analysis and provides a solution for the dynamics of drop migration using extended boundary conditions at the advancing and receding contact lines to account for both Marangoni and Poiseuille flow components, derived approximate drop profiles, and conservation of mass.

Development of a novel and efficient biochar produced from pepper stem for effective ibuprofen removal.

A potential biochar from pepper stems (PS-biochar) was developed via a one-stage pyrolysis process of precursor at 700 °C and employed to adsorb ibuprofen (IBP) in water media. Results showed that PS-biochar was a carbonaceous mesoporous adsorbent with well-developed porosity (S = 727.5 m/g and V = 0.

Absorption and Spreading of a Liquid Droplet Over a Thick Porous Substrate.

Spreading over porous substrates occurs in several processes including printing, cleaning, coating, and manufacturing of ceramic structures. For small drops, viscous and capillary forces are ultimately the predominant forces. The process typically undergoes three phases: a first stage in which the droplet spreads, a second phase in which the area of contact with the solid substrate nearly remains constant, and a third stage in which the droplet retracts with its volume reaching zero finally.

Dynamics of blood flow: modeling of Fåhraeus and Fåhraeus-Lindqvist effects using a shear-induced red blood cell migration model.

Blood flow in micro capillaries of diameter approximately 15-500 μm is accompanied with a lower tube hematocrit level and lower apparent viscosity as the diameter decreases. These effects are termed the Fåhraeus and Fåhraeus-Lindqvist effects, respectively. Both effects are linked to axial accumulation of red blood cells.

Dynamics of blood flow: modeling of the Fåhræus-Lindqvist effect.

To model the Fåhræus-Lindqvist effect, Haynes' marginal zone theory is used, following previous works, i.e., a core layer of uniform red blood cells (RBCs) is assumed to be surrounded by an annular plasma layer in which no RBCs are present.

Electroosmotic-capillary penetration in circular microchannels.

Electroosmotic forces can be used to promote penetration of electrolytes in microcapillaries. Analytical solutions for the dynamics of penetration are provided. The investigation includes both the electroosmotic and Poiseuille flows.

Viscous-gravity spreading of time-varying liquid drop volumes on solid surfaces.

Viscous-gravity spreading of liquid drops of time-dependent volume over a solid surface is considered. A self-similar solution for the drop configuration is obtained, in the case the liquid drop volume varies as a power-law function of time, along with the spreading laws in both cases of cylindrical and axisymmetric geometries. Results compare favorably with published experimental results and previous theoretical work.

Deformation of advancing gas-liquid interfaces in capillary tubes.

Deformation of an advancing gas-liquid meniscus is considered in two cases: prewetted and dry capillary tubes. The shape, slope, and curvature of the gas-liquid interface are determined assuming small Weber and Bond numbers, i.e.