Rate of capillary rise in porous media with nonuniform pores

Dullien, F. A. L.; El-Sayed, MA; Batra, Veera

doi:10.1016/0021-9797(77)90314-9

Cited by 113 publications

(57 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The water-absorption speed of porous media can be characterized by the hydraulic diffusivity, D cap ¼ r c gcosym À 1 , and r c is the effective capillary radius, y is the native contact angle of surface and m is dynamic viscosity of the liquid 47 . If we assume that dry soil becomes fully wet after capillary suction (for example, there are no impenetrable pores), the hydraulic diffusivity can be found using the equation for capillary rise in the absence of gravitational effects: H 2 BD cap t, where H is the rise height and t is time [48][49][50] . The hydraulic diffusivity can be experimentally estimated from capillary rise measurements 50 .…”

Section: Resultsmentioning

confidence: 99%

Aerosol generation by raindrop impact on soil

2015

View full text Add to dashboard Cite

Aerosols are investigated because of their significant impact on the environment and human health. To date, windblown dust and sea salt from sea spray through bursting bubbles have been considered the chief mechanisms of environmental aerosol dispersion. Here we investigate aerosol generation from droplets hitting wettable porous surfaces including various classifications of soil. We demonstrate that droplets can release aerosols when they influence porous surfaces, and these aerosols can deliver elements of the porous medium to the environment. Experiments on various porous media including soil and engineering materials reveal that knowledge of the surface properties and impact conditions can be used to predict when frenzied aerosol generation will occur. This study highlights new phenomena associated with droplets on porous media that could have implications for the investigation of aerosol generation in the environment.

show abstract

Section: Resultsmentioning

confidence: 99%

Aerosol generation by raindrop impact on soil

2015

View full text Add to dashboard Cite

show abstract

“…The effective diameter deff is obtained from solvent impregnation experiments, and the neck diameter dneck is determined from the mercury intrusion measurements. The neck diameter is the smallest pore diameter obtained for half of the mercury saturation [53]. To established the effect of liquid silicon and acid etching on the dbulge and dneck values, compacts with and without heat treatment and/or acid etching were also examined by this way.…”

Section: Infiltration Of Liquid Siliconmentioning

confidence: 99%

“…Some attempts have been made to theoretically model the effect of multiple radii and interconnections on capillarity flow. Dullien et al [53][54] suggested the following equation:…”

Section: Infiltration Of Liquid Siliconmentioning

confidence: 99%

SiC/Si composites elaboration by capillary infiltration of molten silicon

Roger

Guesnet

Marchais

et al. 2018

Journal of Alloys and Compounds

View full text Add to dashboard Cite

Infiltration of molten metal into ceramic performs without external pressure is a promising fabrication method for metal-matrix composites. Thus, this research is focused on the kinetic of capillary infiltration in the processing of Si/SiC composites. The calculation of the infiltration kinetics for a liquid in a porous material is possible by applying the modified-Washburn equation which involves the effective diameter of the pores. This equation implies a K value depending on the wetting angle, the density, the viscosity and the surface tension of the liquid at a given temperature. In this study, the main aim was to measure the K Si value of molten silicon infiltration into porous SiC at 1500°C. On this way, consolidated β-SiC powder compacts were prepared for infiltration experiments. The effects of the SiC particles presintering on the pore size were examined as they can affect molten silicon infiltration. So, the monitoring of the mass increase during hexadecane rise was used to determine the effective diameter of the pores. It was evidenced that an increase of 15.5% of the initial effective diameter occurs. Consequently, a corresponding correction has to be applied to the initial effective diameter of the siliconinfiltrated compacts. Infiltrations of pure molten silicon into SiC compacts were successfully carried out at 1500°C under high vacuum (5.10 -3 mbar) and the average value of K Si was found equal to (5.8±0.4)×10 -6 cm 5 .s.g -2 . The effect of molten silicon rise on the porosity was also considered.

show abstract

“…La meteorización salina también contribuye a la descomposición mecánica producida por las heladas. Los ciclos disolución-cristalización de sales se suelen producir por aguas de lluvia o procesos de condensación (16)(17)(18)(19)(20)(21). El sulfato sódico produce presiones de cristalización muy elevadas.…”

Section: Discussionunclassified

“…Temperate climates such as the case of the Valley of Fallen, with frequent freezing and thawing, are effective drivers of mechanical weathering. Salt weathering in the rock sculpture enhance the mechanical decay produced by frost action and crystallisation-dissolution cycles, where salt dissolution is produced by condensed and/or rain waters (16)(17)(18)(19)(20)(21). In the sodium sulphate system the dissolution of the lower hydrate and the precipitation of the hydrated salt leads to high crystallisation pressures.…”

Section: Procesos De Meteorización En Las Esculturasmentioning

confidence: 99%

Materiales de construcción incompatibles dentro de las esculturas estereotómicas de Avalos en el Valle de Caídos (Madrid, España)

et al. 2012

View full text Add to dashboard Cite

The examination of the recently open pit in top of head of the Piety sculpture of Avalos confirms that the external outer of Black Limestone Calatorao (BLC) composite is made by slabs 20 cm thick joined with gypsum mortars without aggregates. The analyses of these mortars samples performed by optical microscopy (OM), X-ray diffraction (XRD) and Environmental Scanning Electron Microscopy with Energy Dispersive Spectrometry (ESEM-EDS) techniques show hydrous admixtures composed by portlandite, mirabilite, ettringite, thaumasite and gypsum, all of them are well-know dangerous phases for a suitable preservation of the architectural heritage. The huge stereotomic structures have open access to the raining waters reaching the internal core of the sculptures made by concrete with weathered alkali-feldspar aggregates providing sodium to the surrounding sulfated environment facilitating the formation of hydrous calcium and sodium sulfates such as ettringite and mirabilite which reduces the inter-grains adherence.

show abstract

Rate of capillary rise in porous media with nonuniform pores

Cited by 113 publications

References 11 publications

Aerosol generation by raindrop impact on soil

Aerosol generation by raindrop impact on soil

SiC/Si composites elaboration by capillary infiltration of molten silicon

Materiales de construcción incompatibles dentro de las esculturas estereotómicas de Avalos en el Valle de Caídos (Madrid, España)

Contact Info

Product

Resources

About