Method for measuring the saturated permeability coefficient of compacted bentonite at temperatures exceeding 100 °C

Abstract Mine water inrush is one of the important factors threatening safe production in mines. The accurate understanding of the mine groundwater flow field can effectively reduce the hazards of mine water inrush. Numerical simulation is an important method to study the groundwater flow field. This paper numerically simulates the groundwater seepage field in the GaoSong ore field. In order to ensure the accuracy of the numerical model, the research team completed 3,724 field fissure measurements in the study area. The fracture measurement results were analyzed using the GEOFRAC method and the whole-area fracture network data were generated. On this basis, the rock mass permeability coefficient tensor of the aquifer in the study area was calculated. The tensor calculation results are used in the numerical model of groundwater flow. After calculation, the obtained numerical model can better represent the groundwater seepage field in the study area. In addition, we designed three different numerical models for calculation, mainly to explore the influence of the tensor assignment of permeability coefficient on the calculation results of water yield of the mine. The results showed that irrational fathom tensor assignment would cause a significant deviation in calculation results.

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Permeability to albumin in isolated coronary venules

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1993.265.2.h543 ◽

1993 ◽

Vol 265 (2) ◽

pp. H543-H552 ◽

Cited By ~ 7

Author(s):

Y. Yuan ◽

W. M. Chilian ◽

H. J. Granger ◽

D. C. Zawieja

Keyword(s):

Permeability Coefficient ◽

Filtration Rate ◽

Intraluminal Pressure ◽

Apparent Permeability ◽

Filtration Pressure ◽

Diffusive Permeability ◽

Apparent Permeability Coefficient ◽

Chemical Conditions ◽

Physical And Chemical ◽

Intravascular Pressure

This study reports measurements of albumin permeability in isolated coronary venules. The isolated microvessel technique allows the quantification of transmural exchange of macromolecules under tightly controlled physical and chemical conditions. Transvenular exchange of albumin was studied in isolated coronary venules during alterations in filtration rate caused by changes in intravascular pressure. The apparent permeability coefficient of albumin (Pa) at an intraluminal pressure of 11 cmH2O was 3.92 +/- 0.43 x 10(-6) cm/s. Elevating intraluminal pressure to 16 and 21 cmH2O increased Pa to 5.13 +/- 0.57 x 10(-6) and 6.78 +/- 0.66 x 10(-6) cm/s, respectively. Calculation of the true diffusive permeability coefficient of albumin (Pd) at zero filtration rate was 1.54 x 10(-6) cm/s. The product of hydraulic conductance (Lp) and (1 - sigma), where sigma is the solute reflection coefficient, was 3.25 x 10(-7) cm.s-1 x cmH2O-1. At a net filtration pressure of 4-5 cmH2O, diffusion accounts for > 60% of total albumin transport across the venular wall. Transmural albumin flux is very sensitive to filtration rate, rising 6.7% for each cmH2O elevation of net filtration pressure. At 11 cmH2O net filtration pressure, convection accounts for nearly 70% of net albumin extravasation from the venular lumen. We suggest that the isolated coronary venule is a suitable preparation for the study of solute exchange in the heart.

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Analysis of Tunnel Water Inrush Considering the Influence of Surrounding Rock Permeability Coefficient by Excavation Disturbance and Ground Stress

Applied Sciences ◽

10.3390/app11083645 ◽

2021 ◽

Vol 11 (8) ◽

pp. 3645

Author(s):

Helin Fu ◽

Pengtao An ◽

Long Chen ◽

Guowen Cheng ◽

Jie Li ◽

...

Keyword(s):

Permeability Coefficient ◽

Water Pressure ◽

Water Inrush ◽

Surrounding Rock ◽

Water Inflow ◽

Calculation Error ◽

External Water Pressure ◽

Ground Stress ◽

External Water ◽

Inflow Prediction

Affected by the coupling of excavation disturbance and ground stress, the heterogeneity of surrounding rock is very common. Presently, treating the permeability coefficient as a fixed value will reduce the prediction accuracy of the water inflow and the external water pressure of the structure, leading to distortion of the prediction results. Aiming at this problem, this paper calculates and analyzes tunnel water inflow when considering the heterogeneity of permeability coefficient of surrounding rock using a theoretical analysis method, and compares with field data, and verifies the rationality of the formula. The research shows that, when the influence of excavation disturbance and ground stress on the permeability coefficient of surrounding rock is ignored, the calculated value of the external water force of the tunnel structure is too small, and the durability and stability of the tunnel are reduced, which is detrimental to the safety of the structure. Considering the heterogeneity of surrounding rock, the calculation error of water inflow can be reduced from 27.3% to 13.2%, which improves the accuracy of water inflow prediction to a certain extent.

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Prediction of air permeability coefficient and water-vapor resistance of 3D textile layer

Journal of the Textile Institute ◽

10.1080/00405000.2021.1883237 ◽

2021 ◽

pp. 1-9

Author(s):

Aušra Gadeikytė ◽

Aušra Abraitienė ◽

Rimantas Barauskas

Keyword(s):

Water Vapor ◽

Permeability Coefficient ◽

Air Permeability

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Development of Rice Bran Mixed Porous Clay Bricks for Permeable Pavements: A Sustainable LID Technique for Arid Regions

Sustainability ◽

10.3390/su13031443 ◽

2021 ◽

Vol 13 (3) ◽

pp. 1443

Author(s):

Fawaz Alharbi ◽

Meshal Almoshaogeh ◽

Md. Shafiquzzaman ◽

Husnain Haider ◽

Md. Rafiquzzaman ◽

...

Keyword(s):

Compressive Strength ◽

Rice Bran ◽

Urban Areas ◽

Stormwater Management ◽

Permeability Coefficient ◽

World Health ◽

Stormwater Treatment ◽

Sustainable Solutions ◽

Permeable Pavements ◽

Clay Bricks

Permeable pavement provides sustainable solutions for urban stormwater management. In this research, the potential of rice bran mixed porous clay bricks were evaluated for permeable pavements. Physical, mechanical and hydrological properties along with stormwater treatment capabilities of the brick samples were assessed. The study found that ratio of rice bran and clay soil has significant impacts on the properties of the produced bricks. Water adsorption and porosity increased with increasing rice bran ratio. Compressive strength of brick samples decreased from 29.6 MPa to 6.9 MPa when the ratio of rice bran was increased from 0% to 20%. The permeability coefficient increased from 4 × 10−4 to 1.39 × 10−2 mm/s with the increase in rice bran from 0% to 30%. The preamble clay bricks were efficient to remove turbidity, total suspended solids (TSS), five days’ biochemical oxygen demand (BOD5), and heavy metals (Mn, Cu, and Zn) from stormwater to meet the World Health Organization (WHO) standard for wastewater reuse application. The bricks with ≤10% of rice bran achieved the American Society for Testing and Materials (ASTM) standard of the desire compressive strength and permeability coefficient for pedestrian and light traffic pavements. The porous bricks prepared in this study can be used to construct permeable pavements and would be a sustainable low impact developments technique for stormwater management in urban areas.

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