Porosity Permeability
Porosity Permeability - Related Videos
01:20
Porosity and Absorption of Aggregate
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2024
Aggregates contain pores of varying sizes; while some are completely enclosed within the particles, others open onto the surface, allowing water to penetrate. The porosity of aggregates is a major factor contributing to the overall porosity of concrete, given that aggregates constitute about three-quarters of concrete's volume. When all pores in an aggregate are filled with water, the aggregate is considered saturated and surface-dry. If left in dry air, water will evaporate until the aggregate...
01:18
Porosity in Cement Paste
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2024
The porosity of concrete is a measure of the void spaces within its structure. These spaces impact its strength and durability significantly. When water and cement interact, a chemical reaction called hydration creates a semi-solid paste. This paste includes combined water, making up approximately 23% of the cement's dry mass, and gel water, which fills minuscule voids known as gel pores, accounting for about 28% of the cement gel volume. The balance of water to cement in the mix is critical—it...
11:52
Microbubble Fabrication of Concave-porosity PDMS Beads
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Cited by 2 •
2015
Procedures used to generate microstructured concave-porosity polydimethylsiloxane beads are presented. Effects of electrolyte concentration and identity within the aqueous phase are particularly emphasized.
06:37
An Assay for Permeability of the Zebrafish Embryonic Neuroepithelium
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Cited by 11 •
2012
We describe a live whole animal quantitative measurement for permeability of the embryonic zebrafish brain. The technique analyzes the ability to retain cerebrospinal fluid and molecules of different molecular weights within the neural tube lumen and quantifies their movement out of the ventricles. This method is useful for determining differences in epithelial permeability and maturation during development and disease.
10:28
Sensitivity Enhancement of Soft Capacitive Pressure Sensors Using a Solvent Evaporation-Based Porosity Control Technique
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Cited by 1 •
2023
A simple and cost-efficient fabrication method based on the solvent evaporation technique is presented to optimize the performance of a soft capacitive pressure sensor, which is enabled by porosity control in the dielectric layer using different mass ratios of the molding PDMS/toluene solution.
FAQs
Similar pore volume does not guarantee similar fluid transport. Permeability is strongly affected by whether pores connect, their sizes, and their geometry. A material may contain substantial void space that is isolated, narrow, or poorly aligned, limiting flow despite its porosity. This distinction is important when comparing rocks, soils, concrete, ceramics, or porous membranes.
A pressure gradient provides the driving force for fluid movement through connected pores. Under these conditions, Darcy’s law commonly relates flow behavior to the pressure difference and the material’s permeability. Larger pressure gradients can promote greater flow, while lower permeability restricts transport. Engineers use this relationship to analyze fluid movement through porous structures.
Pore size, connectivity, and geometry govern how readily fluid can pass through a material. Connected pathways provide continuous routes, while constrictions or irregular arrangements increase resistance to movement. Consequently, permeability reflects the usable structure of the pore network rather than void volume alone. These characteristics help explain transport differences among engineering materials with comparable porosity.
Used together, these properties distinguish how much fluid a material can accommodate from how readily that fluid can move. Their combined interpretation supports predictions of transport through soils, rocks, concrete, ceramics, and porous membranes. Engineers can therefore evaluate storage-related void space alongside flow-related behavior when analyzing subsurface systems, construction materials, or engineered porous products.
Measurements provide material-specific information needed to assess fluid transport rather than relying only on qualitative descriptions of pore structure. The resulting data support engineering analysis of groundwater movement, petroleum recovery, filtration, and porous material performance. They also help evaluate whether a selected material offers suitable transport behavior for energy, environmental, geotechnical, or structural applications.
Porosity and permeability are relevant wherever fluids move through solids or unconsolidated materials. Applications include groundwater modeling, petroleum recovery, filtration, geotechnical engineering, and the design of materials for energy and environmental uses. In each setting, the properties help connect internal void structure with expected fluid transport, supporting analysis of natural formations and engineered systems.