scholarly journals An Experimental and Theoretical Approach to Visualize Dechlorinating Bacteria in Porous Media

2010 ◽  
Author(s):  
Walt McNab ◽  
Eddie Salazar ◽  
Paul Jackson ◽  
Russ Detwiler
Keyword(s):  
Porous Media ◽  
Theoretical Approach ◽  
Dechlorinating Bacteria

scholarly journals A critical evaluation of short columns for estimating the attachment efficiency of engineered nanomaterials in natural soils

2021 ◽  
Author(s):  
Knapp Karin Norrfors ◽  
Vesna Micić ◽  
Olga Borovinskaya ◽  
Frank von der Kammer ◽  
Thilo Hofmann ◽  
...  
Keyword(s):  
Porous Media ◽  
Theoretical Approach ◽  
Critical Evaluation ◽  
Packed Columns ◽  
Engineered Nanomaterials ◽  
Natural Soils ◽  
Attachment Efficiency ◽  
Short Columns ◽  
Homogeneous Porous Media

Short, saturated packed columns are used frequently to estimate the attachment efficiency (α) of engineered nanomaterials (ENMs) in relatively homogeneous porous media, but a combined experimental and theoretical approach to...

On the Characterization of Lifting Forces During the Rapid Compaction of Deformable Porous Media

2009 ◽  
Vol 131 (10) ◽  
Author(s):  
Banafsheh Barabadi ◽  
Rungun Nathan ◽  
Kei-peng Jen ◽  
Qianhong Wu
Keyword(s):  
Porous Media ◽  
Porous Materials ◽  
Pore Pressure ◽  
Theoretical Approach ◽  
Dynamic Compression ◽  
Air Pressure ◽  
Displacement Sensor ◽  
Pressure Relaxation ◽  
Damping Effect ◽  
Consolidation Theory

In a recent paper, Wu et al. (2005, “Dynamic Compression of Highly Compressible Porous Media With Application to Snow Compaction,” J. Fluid Mech., 542, pp. 281–304) developed a novel experimental and theoretical approach to investigate the dynamic lift forces generated in the rapid compression of highly compressible porous media, (e.g., snow layer), where a porous cylinder-piston apparatus was used to measure the pore air pressure generation and a consolidation theory was developed to capture the pore-pressure relaxation process. In the current study, we extend the approach of Wu et al. to various porous materials such as synthetic fibers. The previous experimental setup was completely redesigned, where an accelerometer and a displacement sensor were employed to capture the motion of the piston. The pore-pressure relaxation during the rapid compaction of the porous material was measured. The consolidation theory developed by Wu et al. was modified by introducing the damping effect from the solid phase of the porous materials. One uses Carman–Kozeny’s relationship to describe the change in the permeability as a function of compression. By comparing the theoretical results with the experimental data, we evaluated the damping effect of the soft fibers, as well as that of the pore air pressure for two different porous materials, A and B. The experimental and theoretical approach presented herein has provided an important methodology in quantifying the contributions of different forces in the lift generation inside porous media and is an extension of the previous studies done by Wu et al.

Lift Generation in Soft Porous Media Under Rapid Compaction

2008 ◽  
Author(s):  
Banafsheh Barabadi ◽  
Rungun Nathan ◽  
Qianhong Wu
Keyword(s):  
Porous Media ◽  
Pore Pressure ◽  
Theoretical Approach ◽  
Air Pressure ◽  
Displacement Sensor ◽  
Pressure Relaxation ◽  
Synthetic Fibers ◽  
Damping Effect ◽  
Consolidation Theory ◽  
Soft Porous Media

In a recent paper, Wu et al. (Journal of Fluid Mechanics 542, 281 (2005)) have developed a novel experimental and theoretical approach to investigate the dynamic lift forces generated in the rapid compression of highly compressible porous media, (e.g. snow layer), where a porous cylinder-piston apparatus was used to measure the pore air pressure generation and a consolidation theory was developed to capture the pore pressure relaxation process. In the current study, we extend Wu et al.’s approach to various porous materials such as synthetic fibers. A complete redesign of the previous experimental setup was done, where an accelerometer and a displacement sensor were employed to capture the motion of the piston. The pore pressure relaxation during the rapid compaction of the porous material was measured. The consolidation theory developed by Wu et al. was modified by introducing the damping effect from the solid phase of the materials. One uses Carman-Kozeny’s relationship to describe the change of the permeability as a function of compression. By comparing the theoretical results with the experimental data, we evaluated the damping effect of the soft fibers as well as that of the pore air pressure for two different synthetic fibers, A and B. The experimental and theoretical approach presented herein has provided an important methodology in quantifying the contributions of different forces in the lift generation in soft porous media and is an extension of the previous studies done by Wu and others.

Differential polarization imaging of sickled cells

1988 ◽  
Vol 46 ◽  
pp. 62-63
Author(s):  
Marcos F. Maestre
Keyword(s):  
Optical Properties ◽  
Theoretical Approach ◽  
Polarized Light ◽  
Polarization Microscopy ◽  
Spectroscopic Techniques ◽  
Polarization Imaging ◽  
Circularly Polarized Light ◽  
Circularly Polarized ◽  
Microscopic Scale ◽  
Chiral Structures

Recently we have developed a form of polarization microscopy that forms images using optical properties that have previously been limited to macroscopic samples. This has given us a new window into the distribution of structure on a microscopic scale. We have coined the name differential polarization microscopy to identify the images obtained that are due to certain polarization dependent effects. Differential polarization microscopy has its origins in various spectroscopic techniques that have been used to study longer range structures in solution as well as solids. The differential scattering of circularly polarized light has been shown to be dependent on the long range chiral order, both theoretically and experimentally. The same theoretical approach was used to show that images due to differential scattering of circularly polarized light will give images dependent on chiral structures. With large helices (greater than the wavelength of light) the pitch and radius of the helix could be measured directly from these images.

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