Hamed Aslannejad

• Assistant Professor at Energy& Resources section of Copernicus Institute Sustainable Development, Utrecht University at Utrecht University

Colloid transport through a porous medium changes geometrical and hydraulic properties of the pore space. The impact of this effect depends on the colloid types and pore space surface properties which determine the likelihood of pore clogging. Colloid attachment and subsequent detachment are key factors in pore clogging. In this study, the impact o...

In order to control ink droplet movement into the printing-paper layer, a set of pore-scale two-phase flow simulations were performed. The high-resolution three-dimensional pore space of the paper was obtained using focused ion beam scanning electron microscopy (FIB-SEM). Solving Navier-Stokes equations yielded details about dynamic movement of a d...

Low-salinity water flooding can be effectively used for enhanced oil recovery. Given the complex physical and chemical processes involved, several controlling mechanisms have been proposed to describe oil re-mobilization in the presence of water solution with low salinity. Osmosis and water-in-oil emulsification are among these mechanisms. However,...

The porosity value of swelling granular materials depends on the degree of swelling and the state-of-stress inside the packing. This research focusses on the swelling of a bed of Super Absorbent Polymer (SAP) particles, which are absorbent particles that can absorb 30 to 40 times their initial weight of saline fluids. Due to the complexity of swell...

Coated paper is an example of a multi-layer porous medium, involving a coating layer along the two surfaces of the paper and a fibrous layer in the interior of the paper. The interface between these two media needs to be characterized in order to develop relevant modeling tools. After careful cutting of the paper, a cross section was imaged using f...

Liquid penetration into thin porous media such as paper is often simulated using continuum-scale single-phase Darcy's law. The underlying assumption was that a sharp invasion front percolates through the layer. To explore this ambiguous assumption and to understand the controlling pore-scale mechanisms, we have developed a dynamic pore-network mode...

In this study, the spreading of a liquid droplet on the surface of a fibrous paper and its penetration into the paper is studied. The spreading of the droplet was visualized using confocal microscopy and the penetration depth was quantified using Automatic Scanning Absorptiometry (ASA) measurements. The three-dimensional structure of the paper was...

Flow of the contaminated water through membrane causes fouling and leads to change membrane transport properties. Understanding how membrane hydraulic properties change during the operation is critical for evaluating the performance of membrane and helps to improve their design. In this study, a 3D pore network model is developed to simulate the re...

Modeling morphological and hydraulic properties of thin porous media, such as filter layers and papers is highly relevant to various industries. In our previous studies, the X-ray tomography and FIB-SEM methods were applied to capture micro- and nano-scale pores in uncoated paper and coated layer, respectively. Here, the reconstructed pore structur...

It is reported that temperature rises at wetting front during water infiltration into soil. The temperature goes back to the background value after passage of water front. Different explanations have been provided for source of energy causing temperature spike. Some have contributed it to heat of condensation released due to condensation of vapor o...

Spontaneous imbibition in cellulosic materials is an expanding field of research due to the direct applicability in paper-based microfluidics. Here, we show experimentally, using simultaneous thermal and optical imaging that the temperature at the wetting front during capillary filling of paper is temporarily increased, even if the imbibed fluid an...

In this study, uncoated paper was characterized. Three-dimensional structure of the layer was reconstructed using imaging results of micro-CT scanning with a relatively high resolution ( 0.9 μ m ) . Image analysis provided the pore space of the layer, which was used to determine its porosity and pore size distribution. Representative elementary...

In swelling materials, the hydraulic parameters, such as porosity, permeability, and retention properties depend on the degree of swelling. An example of swelling granular materials are super absorbent polymer (SAP) particles, which can absorb 30-40 times their initial weight of saline fluids within a few minutes. Due to their fast absorption rate,...

In studies of two-phase flow in complex porous media it is often desirable to have an estimation of the capillary pressure-saturation curve prior to measurements. Therefore, we compare in this research the capability of three pore-scale approaches in reproducing experimentally measured capillary pressure-saturation curves. To do so, we have generat...

Paper used in the printing industry generally contains a relatively thin porous coating covering a thicker fibrous base layer. The three-dimensional pore structure of coatings has a major effect on fluid flow patterns inside the paper medium. Understanding and quantifying the flow properties of thin coating layers is hence crucial. Pore spaces with...

The use of natural gas as fuel for solid oxide fuel cell is one of main potentials of this technology to be exploited as an efficient and profitable future power generation source. However, using direct methane (main component of natural gas) in conventional nickel-based fuel cells leads to carbon deposition problem which causes performance failure...

The present work investigates the performance and degradation mechanisms of a Ni-based anode supported Solid Oxides Fuel Cells (SOFC) operating at 800 and 900 degrees C on direct internal reforming of dry and wet natural gas. The catalytic properties of the anode support were first studied to determine safe conditions under which a dry conversion o...

SOFC single cell was fabricated by using cost effective and simple methods like tape casting and screen printing. Anodic and anodic active layer and electrolyte layer were made by tape casting method. Properties and characterization of the cell was examined. Results showed fabricated cell had good microstructure and its performance was comparable t...

SOFC single cell was fabricated by using two simple and most frequently used methods: tape casting and screen printing. Anodic and anodic active layer was made by tape casting method and screen printing method was used to fabricate electrolyte and cathode layer. Properties and performance of the cell were examined and compared with commercial cells...