Colloid attachment is an important retention mechanism. It is influenced by colloid size, pore size, and flow rate, among other factors. In this work, we studied colloid attachment experimentally under various flow rates, as well as colloid release in response to a rapid change of flow rate. Colloid transport experiments under saturated conditions and with different flow rates were conducted in...

The paper reports on experimental modeling of the colloid system composition in natural groundwater. Iron hydroxide is found to be the main component of natural colloid systems. It is shown that silicon compounds and dissolved organic substances (DOS) stabilize iron hydroxide (III), forming a stable colloid system, and preclude coagulation. The presented results suggest that CaCl2 and AlCl3 ele...

Understanding colloid mobilization during transient flow in soil is important for addressing colloid and contaminant transport issues. While theoretical descriptions of colloid detachment exist for saturated systems, corresponding mechanisms of colloid mobilization during drainage and imbibition have not been considered in detail. In this work, theoretical force and torque analyses were perform...

An active line of contemporary research is dedicated to the adsorption and storage hydrogen on metal-doped carbon materials. Using density functional theory van der Waals corrections we have studied molecular dissociative H2 neutral cationic C60Con complexes with n = 1–8. The Co atoms form compact clusters surface fullerene. Dissociative chemisorption one molecule more stable than C60Con, only ...

This study investigated the concentration/time dependent effects of nanosilver colloid on the motionparameters of the ejaculated ram spermatozoa in vitro. After incubation of sperm samples for 30, 60, 120 and 180 min in the presence of nanosilver colloid (0, 0.001, 0.01, 0.1, 1 and 10 ppm), the motion parameters were evaluated by computer assisted sperm analysis. There was a significant (P

We present a transient Boltzmann equation based transport and reaction model for atomic layer deposition ~ALD! at the feature scale. The transport model has no adjustable parameters. In this article, we focus on the reaction step and the postreaction purge steps of ALD. The heterogeneous chemistry model consists of reversible adsorption of a reactant on a single site, and irreversible reaction ...

Janus colloids propelled by light, e.g., thermophoretic particles, offer promising prospects as artificial microswimmers. However, their swimming behavior and its dependence on fluid properties and fluid-colloid interactions remain poorly understood. Here, we investigate the behavior of a thermophoretic Janus colloid in its own temperature gradient using numerical simulations. The dissipative p...

Flotation constitutes a gravity separation process, which originated from the minerals processing field. However, it has, nowadays, found several other applications, as for example in the wastewater treatment field. Concerning the necessary bubble generation method, typically dispersed-air or dissolved-air flotation was mainly used. Various types of biological materials were tested and floated ...