Journal articles: 'Structural permeability'

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Bailey, Adam, Rosalind King, Simon Holford, Joshua Sage, Martin Hand, and Guillaume Backe. "Defining structural permeability in Australian sedimentary basins." APPEA Journal 55, no. 1 (2015): 119. http://dx.doi.org/10.1071/aj14010.

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Declining conventional hydrocarbon reserves have triggered exploration towards unconventional energy, such as CSG, shale gas and enhanced geothermal systems. Unconventional play viability is often heavily dependent on the presence of secondary permeability in the form of interconnected natural fracture networks that commonly exert a prime control over permeability due to low primary permeabiliy of in situ rock units. Structural permeability in the Northern Perth, SA Otway, and Northern Carnarvon basins is characterised using an integrated geophysical and geological approach combining wellbore logs, seismic attribute analysis and detailed structural geology. Integration of these methods allows for the identification of faults and fractures across a range of scales (millimetre to kilometre), providing crucial permeability information. New stress orientation data is also interpreted, allowing for stress-based predictions of fracture reactivation. Otway Basin core shows open fractures are rarer than image logs indicate; this is due to the presence of fracture-filling siderite, an electrically conductive cement that may cause fractures to appear hydraulically conductive in image logs. Although the majority of fractures detected are favourably oriented for reactivation under in situ stresses, fracture fill primarily controls which fractures are open, demonstrating that lithological data is often essential for understanding potential structural permeability networks. The Carnarvon Basin is shown to host distinct variations in fracture orientation attributable to the in situ stress regime, regional tectonic development and local structure. A detailed understanding of the structural development, from regional-scale (hundreds of kilometres) down to local-scale (kilometres), is demonstrated to be of importance when attempting to understand structural permeability.

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Deen, William M., Matthew J. Lazzara, and Bryan D. Myers. "Structural determinants of glomerular permeability." American Journal of Physiology-Renal Physiology 281, no. 4 (October 1, 2001): F579—F596. http://dx.doi.org/10.1152/ajprenal.2001.281.4.f579.

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Recent progress in relating the functional properties of the glomerular capillary wall to its unique structure is reviewed. The fenestrated endothelium, glomerular basement membrane (GBM), and epithelial filtration slits form a series arrangement in which the flow diverges as it enters the GBM from the fenestrae and converges again at the filtration slits. A hydrodynamic model that combines morphometric findings with water flow data in isolated GBM has predicted overall hydraulic permeabilities that are consistent with measurements in vivo. The resistance of the GBM to water flow, which accounts for roughly half that of the capillary wall, is strongly dependent on the extent to which the GBM surfaces are blocked by cells. The spatial frequency of filtration slits is predicted to be a very important determinant of the overall hydraulic permeability, in keeping with observations in several glomerular diseases in humans. Whereas the hydraulic resistances of the cell layers and GBM are additive, the overall sieving coefficient for a macromolecule (its concentration in Bowman's space divided by that in plasma) is the product of the sieving coefficients for the individual layers. Models for macromolecule filtration reveal that the individual sieving coefficients are influenced by one another and by the filtrate velocity, requiring great care in extrapolating in vitro observations to the living animal. The size selectivity of the glomerular capillary has been shown to be determined largely by the cellular layers, rather than the GBM. Controversial findings concerning glomerular charge selectivity are reviewed, and it is concluded that there is good evidence for a role of charge in restricting the transmural movement of albumin. Also discussed is an effect of albumin that has received little attention, namely, its tendency to increase the sieving coefficients of test macromolecules via steric interactions. Among the unresolved issues are the specific contributions of the endothelial glycocalyx and epithelial slit diaphragm to the overall hydraulic resistance and macromolecule selectivity and the nanostructural basis for the observed permeability properties of the GBM.

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Drumond, M. C., and W. M. Deen. "Structural determinants of glomerular hydraulic permeability." American Journal of Physiology-Renal Physiology 266, no. 1 (January 1, 1994): F1—F12. http://dx.doi.org/10.1152/ajprenal.1994.266.1.f1.

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To elucidate which structures determine the resistance to water movement, we used a computational fluid dynamics approach to determine velocity and pressure fields within the glomerular capillary wall. The model included representations of the endothelial fenestrae, basement membrane, and epithelial filtration slits with slit diaphragms. The input data included dimensions of the various structures from previous electron microscopy studies, as well as the hydraulic permeability recently measured for isolated films of glomerular basement membrane in vitro. The hydraulic resistance of the endothelium was predicted to be small, whereas the basement membrane and filtration slits were each found to contribute roughly one-half of the total hydraulic resistance of the capillary wall. It was calculated that, for a given filtrate flux, the pressure drop within basement membrane in vivo is roughly twice that of “bare” or isolated basement membrane, because of the small fraction of basement membrane area exposed. The dominant resistance in the filtration slit was found to be the slit diaphragm. Predicted values for the overall hydraulic permeability of the capillary wall were within the experimental range derived from micropuncture measurements in normal rats. The model should be a useful tool for analyzing the effects of various structural changes on glomerular hydraulic permeability. This is illustrated by applying the model to recent physiological and morphometric data in nephrotic rats.

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Andrew, Matthew. "Permeability Prediction using multivariant structural regression." E3S Web of Conferences 146 (2020): 04001. http://dx.doi.org/10.1051/e3sconf/202014604001.

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A novel method for permeability prediction is presented using multivariant structural regression. A machine learning based model is trained using a large number (2,190, extrapolated to 219,000) of synthetic datasets constructed using a variety of object-based techniques. Permeability, calculated on each of these networks using traditional digital rock approaches, was used as a target function for a multivariant description of the pore network structure, created from the statistics of a discrete description of grains, pores and throats, generated through image analysis. A regression model was created using an Extra-Trees method with an error of <4% on the target set. This model was then validated using a composite series of data created both from proprietary datasets of carbonate and sandstone samples and open source data available from the Digital Rocks Portal (www.digitalrocksporta.org) with a Root Mean Square Fractional Error of <25%. Such an approach has wide applicability to problems of heterogeneity and scale in pore scale analysis of porous media, particularly as it has the potential of being applicable on 2D as well as 3D data.

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Cao, Shuanghua, Zhiliang Lou, Leheng Wang, and Minsi Li. "The Research of Building Air Permeability Based on Building Structural Tightness." Advanced Materials Research 594-597 (November 2012): 2142–45. http://dx.doi.org/10.4028/www.scientific.net/amr.594-597.2142.

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The building air permeability plays a major role in both building energy performance and indoor air quality. The performance of structural tightness is set as an evaluation index of building air permeability, which is employed to analyze the relationship among building air permeability, building construction and window/door air permeability. Based on some assumptions, the coefficient of building structural tightness is established to summarize the influential factors on building air permeability, and the theory method is provided to improve the building air permeability. A model of air permeability for a small room is taken as an example. The results indicate that the building structural tightness coefficient is available to analyze the building air permeability.

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KIM, JAE-SIK, EUI-SUN CHOI, YOUNG-HIE LEE, and KI-WON RYU. "STRUCTURAL AND RF PROPERTIES OFCo2ZFERRITE FOR ANTENNA SUBSTATE." Modern Physics Letters B 23, no. 31n32 (December 30, 2009): 3731–37. http://dx.doi.org/10.1142/s0217984909021764.

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The sintering behavior and high frequency electro-magnetic properties of Ba3Co2Fe24O41ceramics were investigated for the small antenna application. All samples of the Ba3Co2Fe24O41ceramics were prepared by the solid-state reaction method and sintered at 1150°C 1400°C. From the XRD patterns of calcined Ba3Co2Fe24O41powders, the most suitable condition for calcining was 600°C–1000°C. Ba3Co2Fe24O41phase was observed in sintered Ba3Co2Fe24O41ceramics as main phase. Bulk densities increased with sintering temperature and decreased at 1400°C. Permittivity and permeability of the Ba3Co2Fe24O41ceramics increased or decreased with sintering temperature, respectively. On the other hand, loss tangent of permittivity and of permeability showed contrary tendency with permittivity and permeability. The permittivity and loss tangent of permittivity of Ba3Co2Fe24O41ceramics sintered at 1300°C were 19.896 and 0.171 at 210 MHz. and the measured value of permeability and loss tangent of permeability were 14.218 and 0.204, respectively.

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Kikuchi, H., K. Noguchi, T. Liu, K. Ara, Y. Kamada, and S. Takahashi. "Characterization of Structural Materials Using AC Permeability." Journal of the Magnetics Society of Japan 29, no. 5 (2005): 563–66. http://dx.doi.org/10.3379/jmsjmag.29.563.

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8

Real, Sofia, and J. Alexandre Bogas. "Oxygen permeability of structural lightweight aggregate concrete." Construction and Building Materials 137 (April 2017): 21–34. http://dx.doi.org/10.1016/j.conbuildmat.2017.01.075.

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Cǒté, Wilfred A. "Structural factors affecting the permeability of wood." Journal of Polymer Science Part C: Polymer Symposia 2, no. 1 (March 7, 2007): 231–42. http://dx.doi.org/10.1002/polc.5070020122.

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10

Over, Björn, Pär Matsson, Christian Tyrchan, Per Artursson, Bradley C. Doak, Michael A. Foley, Constanze Hilgendorf, et al. "Structural and conformational determinants of macrocycle cell permeability." Nature Chemical Biology 12, no. 12 (October 17, 2016): 1065–74. http://dx.doi.org/10.1038/nchembio.2203.

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Cui, H. Z., W. C. Tang, and T. Y. Lo. "Investigation of Permeability of Structural Lightweight Aggregate Concrete." Advanced Science Letters 15, no. 1 (August 1, 2012): 176–78. http://dx.doi.org/10.1166/asl.2012.4099.

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Liashkovich, Ivan, Anna Meyring, Hans Oberleithner, and Victor Shahin. "Structural organization of the nuclear pore permeability barrier." Journal of Controlled Release 160, no. 3 (June 2012): 601–8. http://dx.doi.org/10.1016/j.jconrel.2012.02.016.

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13

Butvin, P., B. de Ronzyová, and M. Hlásnik. "Permeability disaccommodation and structural stability of metallic glasses." Physica Scripta 40, no. 5 (November 1, 1989): 685–87. http://dx.doi.org/10.1088/0031-8949/40/5/018.

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14

Sibson, Richard H. "Structural permeability of fluid-driven fault-fracture meshes." Journal of Structural Geology 18, no. 8 (August 1996): 1031–42. http://dx.doi.org/10.1016/0191-8141(96)00032-6.

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15

Akhter, Shahida, D. P. Paul, D. K. Saha, S. M. Hoque, and M. A. Hakim. "Structural, Magnetic and Electrical Properties of Cu-Mg Ferrites." Journal of Scientific Research 6, no. 2 (April 23, 2014): 205–15. http://dx.doi.org/10.3329/jsr.v6i2.17351.

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Cu1-xMgxFe2O4 ferrites with (x = 0.2, 0.4, 0.6, 0.8 and 1.0) has been synthesized by double sintering ceramic technique at 11500C for 2hr and investigated for their structure, microstructure, complex permeability behaviour, DC and AC resistivity, dielectric constant measurements. X-ray analysis indicated the formation of single-phase cubic spinel structure for all samples and the lattice parameter was found to decrease with increasing Mg content. Grain size was found to decrease from 34.36 to 4.16 mm with the increase of Mg contents. The real part of initial permeability (??) remained constant up to certain lower range of frequency after it decreased slightly to lower value of permeability at which imaginary part of permeability (?²) showed a maximum value. The decrease of ?? is observed with the increase of Mg content which is attributed to a decrease of grain size. DC electrical resistivity and dielectric constant decreased with increasing Mg content and AC resistivity decreased with increasing frequency, exhibiting normal ferrimagnetic behaviour. The observed variation of electrical and dielectric properties has been explained on the basis of the electronic hopping frequency between Fe2+ and Fe3+ ions in present samples. Keywords: Ferrites; XRD; Micrographs; Complex permeability; DC resistivity. © 2014 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. doi: http://dx.doi.org/10.3329/jsr.v6i2.17351 J. Sci. Res. 6 (2), 205-215 (2014)

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Mathai, John C., Stephanie Tristram-Nagle, John F. Nagle, and Mark L. Zeidel. "Structural Determinants of Water Permeability through the Lipid Membrane." Journal of General Physiology 131, no. 1 (December 31, 2007): 69–76. http://dx.doi.org/10.1085/jgp.200709848.

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Despite intense study over many years, the mechanisms by which water and small nonelectrolytes cross lipid bilayers remain unclear. While prior studies of permeability through membranes have focused on solute characteristics, such as size, polarity, and partition coefficient in hydrophobic solvent, we focus here on water permeability in seven single component bilayers composed of different lipids, five with phosphatidylcholine headgroups and different chain lengths and unsaturation, one with a phosphatidylserine headgroup, and one with a phosphatidylethanolamine headgroup. We find that water permeability correlates most strongly with the area/lipid and is poorly correlated with bilayer thickness and other previously determined structural and mechanical properties of these single component bilayers. These results suggest a new model for permeability that is developed in the accompanying theoretical paper in which the area occupied by the lipid is the major determinant and the hydrocarbon thickness is a secondary determinant. Cholesterol was also incorporated into DOPC bilayers and X-ray diffuse scattering was used to determine quantitative structure with the result that the area occupied by DOPC in the membrane decreases while bilayer thickness increases in a correlated way because lipid volume does not change. The water permeability decreases with added cholesterol and it correlates in a different way from pure lipids with area per lipid, bilayer thickness, and also with area compressibility.

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Fu, Bingmei M., and Shang Shen. "Structural mechanisms of acute VEGF effect on microvessel permeability." American Journal of Physiology-Heart and Circulatory Physiology 284, no. 6 (June 1, 2003): H2124—H2135. http://dx.doi.org/10.1152/ajpheart.00894.2002.

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To investigate the ultrastructural mechanisms of acute microvessel hyperpermeability by vascular endothelial growth factor (VEGF), we combined a mathematical model ( J Biomech Eng 116: 502–513, 1994) with experimental data of the effect of VEGF on microvessel hydraulic conductivity ( L p) and permeability of various-sized solutes. We examined the effect of VEGF on microvessel permeability to a small solute (sodium fluorescein, Stokes radius 0.45 nm), an intermediate solute (α-lactalbumin, Stokes radius 2.01 nm), and a large solute [albumin (BSA), Stokes radius 3.5 nm]. Exposure to 1 nM VEGF transiently increased apparent permeability to 2.3, 3.3, and 6.2 times their baseline values for sodium fluorescein, α-lactalbumin, and BSA, respectively, within 30 s, and all returned to control within 2 min. On the basis of L p (DO Bates and FE Curry. Am J Physiol Heart Circ Physiol 271: H2520–H2528, 1996) and permeability data, the prediction from the model suggested that the most likely structural changes in the interendothelial cleft induced by VEGF would be a ∼2.5-fold increase in its opening width and partial degradation of the surface glycocalyx.

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Li, Xi Hong, Kuan Guo, and Xiao Yan Zhao. "Effect of Beeswax on Functional and Structural Properties of Soy Protein Isolate Films." Advanced Materials Research 150-151 (October 2010): 1396–99. http://dx.doi.org/10.4028/www.scientific.net/amr.150-151.1396.

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This paper explains and demonstrates the effects of beeswax on functional and structural properties of soy protein isolate films, containing different glycerol. The results showed that percentage elongation at break, water vapor permeability, and transparency of soy protein isolate films decreased when the beeswax content increased, but tensile strength and oxygen permeability increased. The higher the glycerol content, the higher the film water vapor permeability, oxygen permeability, and transparency. The results of differential scanning calorimetry and Fourier transform infrared spectroscopy suggested that beeswax cross-linked with soy protein isolate molecules via connecting with glycerol, composed the film matrix.

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Zeng, Sheng, Kai Xuan Tan, Xue Ming Du, and Chun Guang Li. "The Effects of Structural Characteristics of Low Seepage Sandstone Uranium Ore Rock on Permeability." Advanced Materials Research 524-527 (May 2012): 371–74. http://dx.doi.org/10.4028/www.scientific.net/amr.524-527.371.

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It is great important for the development of China’s uranium mining to efficiently extract low seepage sandstone uranium ore rock. It is the objective of this paper to present the effects of the structural characteristics of the low seepage sandstone uranium ore rock on permeability. Samples of sandstone from a uranium mine in XinJiang province were used to carry out experimental research on permeability. These tests were carried out on ore rock with particle size and distribution characteristics determined by a homemade permeability test device. The research indicates that the sandstone uranium deposits may be classified as low seepage because the particle size falls within the range 0.1~1.6mm, that the distribution of particle sizes observed conforms to low seepage fractal characteristics, the permeability decreases when the value of the ore particle size distribution of fractal dimensions increases, and the permeability decreases with particle size decreasing, and that the decrease of the permeability is not a linear change, but is an obviously exponentially decreasing functional relationship.

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Zhu, Guocheng, Yuan Fang, Lianying Zhao, Jinfeng Wang, and Weilai Chen. "Prediction of structural parameters and air permeability of cotton woven fabric." Textile Research Journal 88, no. 14 (April 25, 2017): 1650–59. http://dx.doi.org/10.1177/0040517517705632.

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Air permeability is a very important property influencing the performance of clothing comfort and technical textiles particularly in applications for protective products, including airbags, parachutes, and tents. Several analytical models for predicting air permeability have been made by considering porosity and pore diameter or porous area. However, the connection between fabric structure and air permeability with analytical models has not been well reported as yet. In this work, the diameter of cotton yarn was predicted by considering yarn count, twist, and packing density. Subsequently, the pore area and equivalent pore diameter of fabric were predicted after finding the warp and the weft densities of fabric. The predicted values had very good agreement with the experimental results in yarn diameter and other structural parameters of fabric. The air permeability of fabrics was measured and several well-known analytical models for predicting air permeability were compared. The results revealed that the Hagen–Poiseuille equation had much better prediction than other models and also had good agreement with the experimental results, especially when it was applied for tight fabrics at low pressure drop (≤60 Pa). The Hagen–Poiseuille equation could be improved by considering the Reynolds number, interfiber interstices, and the deformation of pores under higher pressure drop.

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Zhang, Lianyang. "Aspects of rock permeability." Frontiers of Structural and Civil Engineering 7, no. 2 (April 21, 2013): 102–16. http://dx.doi.org/10.1007/s11709-013-0201-2.

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Gu, Wen Huan, Yue Tian Liu, Xiao Di Fu, and Fei Fei Luo. "Exploration of Calculation Method about Structural Parameters of Big Channels in Unconsolidated Sandstone Reservoirs." Advanced Materials Research 347-353 (October 2011): 1669–72. http://dx.doi.org/10.4028/www.scientific.net/amr.347-353.1669.

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The Volume calculation model of big channels is established based on percolation echanics theory. The permeability calculation model of big channels is on the basis of high-speed non-Darcy fluid flowing in big channels. Big channels inunconsolidated sandstone reservoirs exist in incomplete developed form and complete development form. And the percolation indexes vary in different stages of development. Research results show that permeability of big channels when percolation index is 0.5 differs from permeability of big channels calculated according to linear Darcy flow with a ifference of 15.8 times. Confirming the percolation index n accurately is the premise of calculating permeability in big channels and the average radius.

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Qutob, Dinah, Fengshan Ma, Carol A. Peterson, Mark A. Bernards, and Mark Gijzen. "Structural and permeability properties of the soybean seed coat." Botany 86, no. 3 (March 2008): 219–27. http://dx.doi.org/10.1139/b08-002.

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The seed coat is a composite structure that serves as a conduit for nutrient acquisition for the developing embryo. Upon seed desiccation and maturation, the seed coat provides cover and protection for the embryo and may impose dormancy or trigger germination by controlling water uptake. For crop plants such as soybean, traits determined by the seed coat impact the overall quality of the seed and the utility of its derived products. There are remarkable examples of unusual genetic mechanisms that control seed coat pigmentation, lustre, and cracking that have been recently described in soybean. Studies on seed permeability to water have resulted in the formulation of new hypotheses to account for variation of this trait. This review summarizes the current advances in our understanding of the structural properties of the soybean seed coat with an emphasis on the control of permeability to water in mature seeds.

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Over, Björn, Pär Matsson, Christian Tyrchan, Per Artursson, Bradley C. Doak, Michael A. Foley, Constanze Hilgendorf, et al. "Erratum: Structural and conformational determinants of macrocycle cell permeability." Nature Chemical Biology 13, no. 8 (July 18, 2017): 922. http://dx.doi.org/10.1038/nchembio0817-922a.

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Burton, Philip S., Robert A. Conradi, Norman F. H. Ho, Allen R. Hilgers, and Ronald T. Borchardt. "How Structural Features Influence the Biomembrane Permeability of Peptides." Journal of Pharmaceutical Sciences 85, no. 12 (December 1996): 1336–40. http://dx.doi.org/10.1021/js960067d.

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Zhu, Xuefeng, You Cong, and Weishen Yang. "Oxygen permeability and structural stability of BaCe0.15Fe0.85O3−δ membranes." Journal of Membrane Science 283, no. 1-2 (October 2006): 38–44. http://dx.doi.org/10.1016/j.memsci.2006.06.010.

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Almasalmeh, Abdulnasser, Dawid Krenc, Binghua Wu, and Eric Beitz. "Structural determinants of the hydrogen peroxide permeability of aquaporins." FEBS Journal 281, no. 3 (December 13, 2013): 647–56. http://dx.doi.org/10.1111/febs.12653.

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Zahn, Michael, Satya Prathyusha Bhamidimarri, Arnaud Baslé, Mathias Winterhalter, and Bert van den Berg. "Structural Insights into Outer Membrane Permeability of Acinetobacter baumannii." Structure 24, no. 2 (February 2016): 221–31. http://dx.doi.org/10.1016/j.str.2015.12.009.

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Luque, P., S. Bruque, and A. Heredia. "Water Permeability of Isolated Cuticular Membranes: A Structural Analysis." Archives of Biochemistry and Biophysics 317, no. 2 (March 1995): 417–22. http://dx.doi.org/10.1006/abbi.1995.1183.

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Park, Jung Hoon, and Sang Do Park. "Oxygen permeability and structural stability of La0.6Sr0.4Co0.2Fe0.8O3−δ membrane." Korean Journal of Chemical Engineering 24, no. 5 (September 2007): 897–905. http://dx.doi.org/10.1007/s11814-007-0062-2.

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Zoppetti, G., I. Caramazza, Y. Murakami, and T. Ohno. "Structural requirement for duodenal permeability of heparin-diamine complexes." Biochimica et Biophysica Acta (BBA) - General Subjects 1156, no. 1 (December 1992): 92–98. http://dx.doi.org/10.1016/0304-4165(92)90101-y.

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Groenevelt, P. H., and G. G. Lemoine. "On the measurement of air permeability." Netherlands Journal of Agricultural Science 35, no. 3 (August 1, 1987): 385–94. http://dx.doi.org/10.18174/njas.v35i3.16733.

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Air pemeability values are used to assess the state of aeration, soil structural stability, structural degradation and compaction. A simple experimental procedure, using a constant-speed motor, a syringe and simple pressure sensors, is discussed. At steady-state air flow throught a soil sample the air permeability coefficient can be derived directly from Kirkham's equation. For transient conditions an equation is presented, based on a combination of Kirkham's equation and the ideal gas law, from which the air permeability coefficient can be deduced by trial and error. The importance of the soil water potential, in relation to the measurement of air permeability, is discussed. Complications arising from the 'non-ideal' behaviour of the pressure sensor are also discussed. (Abstract retrieved from CAB Abstracts by CABI’s permission)

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Ling, Wei Wei, Yuan Xun Li, Hai Nie, and Huai Wu Zhang. "Structural and Magnetic Properties of Low Temperature Fired Ferrite/Ceramic Composite Materials." Advanced Materials Research 466-467 (February 2012): 361–65. http://dx.doi.org/10.4028/www.scientific.net/amr.466-467.361.

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MgCuZn ferrite/CaTiO3and MgCuZn ferrite/BaTiO3composites which can be applied in low temperature co-fired ceramic (LTCC) technology were synthesized by conventional solid-state reaction at 950°C. The sintering behavior and microstructures of the samples have been analyzed. The complex permeability spectra of the above two composites have been investigated. The contribution of spin rotation and domain wall motion to the permeability spectra was estimated by the numerical fitting of measured data to the relevant formula. Influence of two types of magnetizing processes on the permeability of different composites has been analyzed combining with the variation of microstructures.

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Ma, Xiang, Hao Wang, and Peisheng Zhou. "Novel Gradation Design of Porous Asphalt Concrete with Balanced Functional and Structural Performances." Applied Sciences 10, no. 20 (October 9, 2020): 7019. http://dx.doi.org/10.3390/app10207019.

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To improve the permeability of porous asphalt concrete (PAC) with a small nominal maximum aggregate size (NMAS) of 10 mm (PAC10), a novel gradation design by excluding the 0.075–3 mm aggregate was developed. This study aims to evaluate the functional and structural performances of the novel PAC10 with various mineral filler contents, using the conventional PAC10 and 13 mm NMAS PAC (PAC13) as reference, and develop the optimum gradation of the novel PAC10. The performance properties evaluated include moisture susceptibility, durability, high-temperature stability, low-temperature cracking resistance and permeability. The results indicated that for the two conventional PACs with the same fine aggregate and mineral filler content, PAC10 had worse permeability and rutting resistance, similar moisture susceptibility and durability, and better low-temperature cracking resistance, compared with the PAC13. The novel PAC10 showed better permeability than the conventional PAC10. With the increase of the mineral filler content, the structural performance of the novel PAC10 is improved, but its permeability is decreased. With a mineral filler content of 6%, the novel PAC10 can have balanced functional and structural performances, which are equivalent to those of the conventional PAC13.

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Sagoe–Crentsil, Kwesi, Trevor Brown, and Shi Qin Yan. "Medium to Long Term Engineering Properties and Performance of High-Strength Geopolymers for Structural Applications." Advances in Science and Technology 69 (October 2010): 135–42. http://dx.doi.org/10.4028/www.scientific.net/ast.69.135.

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The medium to long term engineering performance of high-strength geopolymer concrete systems are largely dependent on fluid ingress and the transport phenomena that govern permeability of structural members exposed to aggressive environments. For the purpose of analysing durability performance, both high pressure water and gas permeability testing of fly-ash geopolymer(GP) concretes have been assessed for samples cured under ambient and steam exposure conditions at 65OC. The observed mean permeability coefficient values for gas(k) and water(Kw) of steam-cured structural grade concrete was respectively 6.19E-17m2 at 300kPa gas pressure and 1.52E-10m/s at 525kPa water pressure. While mean gas permeability values were comparable to reference steam-cured ordinary Portland cement(OPC) systems, the corresponding water permeability coefficient data for geopolymer concrete was ten-fold higher. The transport properties of OPC concrete systems are typically governed by water-to-cement ratio and the degree of hydration which is linked to the level of porosity and pore interconnectivity. However, corresponding permeability of geopolymer concrete appears to be dictated by an inherent mesoporous capillary pore network structure for which transport properties appear to be partly dependent on mode of concrete curing. The Paper examines global implications of increased permeability and key durability parameters such as chloride diffusion, carbonation rates and steel reinforcement corrosion on long-term engineering and durability performance.

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Kacprzak, G., C. Boutin, and T. Doanh. "Permeability of Sand-Clay Mixtures." Archives of Civil Engineering 56, no. 4 (December 1, 2010): 299–320. http://dx.doi.org/10.2478/v.10169-010-0017-6.

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Abstract This study deals with the behavior of composite blends constituted of rigid and impervious grains included in saturated clay paste of kaolin, considered as permeable and deformable. Permeability tests performed during standard oedometr tests (before each load step) highlight the key role of the original and actual state of the clay paste, and show the existence of a threshold of sand grain concentration above which a structuring effect influences its permeability. In the light of these experiments some usual homogenization methods (with simplifying assumptions to make the problem manageable) are considered in order to model the mixture permeability. Qualitative and quantitative comparisons with experimental data point out their respective domain of interest and limitations of such approaches

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Hao, Yan Zhou, Lei Cheng, and Wen Fang Xiao. "Experimental Study on Permeability Anisotropy of Unsaturated Compacted Loess." Advances in Civil Engineering 2022 (January 19, 2022): 1–14. http://dx.doi.org/10.1155/2022/9348604.

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This study investigates the permeability characteristics of unsaturated compacted loess by focusing on the anisotropy parallel and perpendicular to the compaction. Three tests are conducted on compacted loess: permeability test, soil-water characteristic curve test, and scanning electron microscope (SEM) test. Samples are maintained and tested at different dry densities under optimal moisture conditions. Test results showed that the horizontal saturated permeability coefficient of compacted loess was larger than in the vertical direction, showing obvious anisotropy. Based on the saturated permeability coefficient, the permeability coefficient of unsaturated compacted loess can be predicted according to the soil-water characteristic curve fitted using the van Genuchten model combined with the Childs and Collis-Geroge model. The relational formula was established between the unsaturated permeability anisotropy ratio and the matrix suction through introducing a pore connectivity-tortuosity parameter, which represents the relationship between unsaturated permeability anisotropy ratio and matrix suction. The difference of pore characteristics between horizontal and vertical directions of compacted loess is the main reason for the permeability anisotropy.

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Zhang, Zhenying, Xiufeng Pan, Jiahe Zhang, and Hui Xu. "Effect of Particle Size on the Hydraulic Characteristics of Mechanically and Biologically Treated Waste." Advances in Civil Engineering 2020 (September 19, 2020): 1–13. http://dx.doi.org/10.1155/2020/8888550.

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Mechanical biological treatment (MBT) is a waste processing technology that helps conserve resources and reduce emissions harmful to the environment. The treatment of municipal solid waste (MSW) using MBT is a hot topic in environmental geotechnical engineering. Permeability tests were carried out on MBT waste using a compression and permeability combined apparatus and a large-scale vertical permeability apparatus taking the influence of particle size into consideration. The permeability of samples with smaller particle sizes was found to be lower for the same pressure and dry mass (%) of component. The best-fit line between the logarithmic permeability and variables such as the dry density was linear. As the dry density increased or the void ratio decreased, the permeability of samples with smaller particles decreased more. The logarithmic permeability increased with the increase in the average particle size and void ratio. The permeabilities of MBT waste corresponding to particle size ranges of 0–10, 0–20, and 0–40 mm were 10−10–10−5, 10−8–10−4, and 10−5–10−3 m/s, respectively. The difference between MBT waste and MSW was analyzed in terms of their permeability. The results of MBT waste were compared with those reported in previous studies to provide reference for the permeability analysis of MBT landfills.

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39

Bagaiskov, Yu. "Influence of gas permeability of abrasive tools on their structural and mechanical parameters." Journal of Physics: Conference Series 2131, no. 5 (December 1, 2021): 052043. http://dx.doi.org/10.1088/1742-6596/2131/5/052043.

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Abstract Quality assurance and processing capacity are essential performance parameters of abrasive tools. It is of prime importance for grinding wheels operating at a speed of 35–60 m/s. In this case, the opportunities to increase the high-rate grinding efficiency without burns are associated with using high-porosity and low-hardness wheels. Artificial pore-forming agents are used to manufacture tools. Introduction of pore-forming agents decreases grinding forces and increases the maximum grinding depth without burns. The porosity of filled compound materials can be attributed to the conception of gas permeability. The gas permeability parameter describes the openness degree of such structures and the velocity of the air volumes passing through porous materials. The porosity and gas-permeability degrees of the material of high-porous ceramic-bond abrasive tools with various parameters, depending on the abrasive material type, porogen grain size and content, and the composite structure number have been studied. It appeared that the porosity degree of high-porous abrasive tools, made both of fused alumina and silicon carbide increases as the structure number, grain size, and content of burning porogens increases. Besides, the increase degree of fused alumina is a little higher than that of silicon carbide. The gas permeability degree depends on the factors mentioned above in nearly the same way. Compared to porosity, the effect of gas permeability increases due to an altered structure, grain size, and content of porogens is much higher, up to 6 times. In this case, the gas permeability value is primarily characteristic of the pore size; in other words, the speed and volume of the air or lubrication and cooling fluid penetrating the material structure increase correspondingly at nearly the same increase of the pore size by several times and at the same volume porosity degree. The gas permeability degree can be used for quantitative and qualitative description of the material structure of high-porous abrasive tools, as well as their structural and mechanical parameters. The operating parameters of tools can depend on the gas permeability level of their materials. Thus, the results of abrasive processing can be foreseen.

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40

Zhu, Xinmin, Guannan Liu, Feng Gao, Dayu Ye, and Jixi Luo. "A Complex Network Model for Analysis of Fractured Rock Permeability." Advances in Civil Engineering 2020 (October 29, 2020): 1–10. http://dx.doi.org/10.1155/2020/8824082.

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Fractured rocks exist widely in nature. The fracture network is an effective storage space and main seepage channel of low-permeability oil and gas reservoirs, which controls the seepage system of low-permeability oil and gas reservoirs. The connection characteristics of fracture networks are complex and evolve dynamically with time. The rise of complex network research can provide reliable analysis for the relationship between network structures and network behaviors. In this work, the fracture network is considered as a hierarchical network with self-similarity, and complex network theory is applied to analyze the permeability of fractured rocks. According to the power-law relationship of degree distribution of network nodes, the number of nodes is corresponding to the number of network edges and a new power-law distribution relationship of edges with degree of nodes is proposed. Eventually, the permeability model of fractured rocks is derived and it is found that permeability of fractured rocks is a function of degree of maximum node k max , self-similarity index γ , power index d k , and other structural parameters. Compared with the existing numerical simulations, the validity of the model is verified. By calculating the influence of model parameters on the permeability, the following results are obtained: (1) fracture porosity is directly proportional to permeability; (2) fracture surface density is linearly increasing with permeability; (3) power index is inversely proportional to permeability; and (4) permeability is exponentially increasing with the maximum degree of a node.

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Hao, Yan-zhou, Tie-hang Wang, Xin Jin, Lei Cheng, and Jiang-le Li. "Experimental Study on the Saturated Compacted Loess Permeability under K0 Consolidation." Advances in Civil Engineering 2020 (February 29, 2020): 1–16. http://dx.doi.org/10.1155/2020/1426485.

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This paper investigates the permeability characteristics of compacted loess by focusing on the anisotropy parallel and perpendicular to the compaction. Three tests are conducted on compacted loess: triaxial permeability test under confining pressure consolidation, triaxial permeability test under K0 consolidation, and SEM test. Samples are maintained and tested at different dry densities under saturated conditions. The test results show that the saturated permeability coefficient of compacted loess is exponentially related to the initial dry density under both confining pressure consolidation and K0 consolidation. The fitting equation can estimate the saturated permeability coefficient of compacted loess at different depths. The horizontal saturated permeability coefficient of compacted loess is larger than that in the vertical direction, showing obvious anisotropy. The saturated permeability anisotropy ratio is linearly related to the initial dry density. Comparing and analysing the saturated permeability coefficient, the saturated permeability coefficient of compacted loess under the K0 consolidation condition is smaller than that under the confining pressure consolidation condition. Under the condition of K0 consolidation, the connectivity of vertical and horizontal pores of compacted loess is weakened, the tortuosity is strengthened, and the void ratio is decreased. K0 consolidation makes the flake-, plate-, and needle-like particles in compacted loess rotate continuously parallel to the compaction surface, which enhances the orientation of particles and leads to the saturated permeability anisotropy increase. The research results provide the basis for water field analysis in loess filling engineering.

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42

Ribic-Zelenovic, L., M. Spasojevic, A. Maricic, and M. M. Ristic. "The effect of structural changes during sintering on the electric and magnetic traits of the Ni96.7Mo3.3 alloy nanostructured powder." Science of Sintering 41, no. 2 (2009): 175–84. http://dx.doi.org/10.2298/sos0902175r.

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Ni96.7Mo3.3 powder was electrochemically obtained. An X-ray diffraction analysis determined that the powder consisted of a 20% amorphous and 80% crystalline phase. The crystalline phase consisted of a nanocrystalline solid nickel and molybdenum solution with a face-centred cubic (FCC) lattice with a high density of chaotically distributed dislocations and high microstrain value. The scanning electronic microscopy (SEM) showed that two particle structures were formed: larger cauliflower-like particles and smaller dendriteshaped ones. The thermal stability of the alloy was examined by differential scanning calorimetry (DSC) and by measuring the temperature dependence of the electrical resistivity and magnetic permeability. Structural powder relaxation was carried out in the temperature range of 450 K to 560 K causing considerable changes in the electrical resistivity and magnetic permeability. Upon structural relaxation, the magnetic permeability of the cooled alloy was about 80% higher than the magnetic permeability of the fresh powder. The crystallisation of the amorphous portion of the powder and crystalline grain increase occurred in the 630 K to 900 K temperature interval. Upon crystallisation of the amorphous phase and crystalline grain increase, the powder had about 50% lower magnetic permeability than the fresh powder and 3.6 times lower permeability than the powder where only structural relaxation took place.

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Blaž, Nelu, Andrea Marić, Goran Radosavljević, Ibrahim Atassi, Walter Smetana, and Ljiljana Živanov. "Comparison of Magnetic Characteristics and Structural Properties of Commercially Available Ferritic LTCC Materials." Additional Conferences (Device Packaging, HiTEC, HiTEN, and CICMT) 2012, CICMT (September 1, 2012): 000359–64. http://dx.doi.org/10.4071/cicmt-2012-wa42.

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The complex permeability values are the key parameters that determine properties of ferrite components. These parameters are very dependent on material structural properties and composition. This paper presents comparison of magnetic and structural properties of commercially available LTCC materials ESL 40011 and ESL 40012. The characterization sample, for each material, is a stack of LTCC tapes forming a toroidal shape structure sintered at peak temperatures of 885 °C. For both samples, scanning with electronic microscope was performed in order to determine differences in grain size and porosity. Energy-dispersive spectroscopy (EDS) was used for the elemental analysis of the samples. Obtained EDS spectrum for each samples are compared and analyzed. Permeability, for both materials are determined in the frequency range from 10 kHz to 1 GHz. Measurement procedures are divided in two segments - for low and high frequencies. For low frequency measurements method (from 10 kHz to 1000 kHz) with discrete turns of wire is performed using LCZ meter. On higher frequency range (from 1000 kHz to 1 GHz) method with short coaxial sample holder and Vector Network Analyzer is used. Obtained characteristics for complex permeability are presented and analyzed. It was determine that ESL 40011 has lower value for complex permeability but higher frequency range than ESL 40012. LTCC material ESL 40011 have maximal value 263 for real part of complex permeability at 2.3 MHz and ESL 40012 have maximal value 678 for real part of complex permeability at 0.5 MHz. Additionally, dispersion parameters of analyzed feritic materials are determined and compared.

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Bickley, J. A., J. Ryell, C. Rogers, and R. D. Hooton. "Some characteristics of high-strength structural concrete." Canadian Journal of Civil Engineering 18, no. 5 (October 1, 1991): 885–89. http://dx.doi.org/10.1139/l91-107.

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The 68-storey Scotia Plaza tower in Toronto is an outstanding example of the use of concrete technology to achieve high-performance high-strength concrete. Cementitious hydraulic slag, silica fume, and a superplasticizer were combined with CSA type-10 Portland cement and high-quality aggregates to produce very workable high-strength concrete. During the course of construction, data were published suggesting the possibility of the strength regression of some silica fume concretes after long exposure to low humidity, the determinations being made on standard test cylinders. Tests were, therefore, made at ages of 1 year and 2 years on specimens drilled from columns in the structure. This technical note gives details of the laboratory examination and testing of these specimens. Key words: high strength, slag, silica fume, permeability, rapid chloride permeability, petrographic examination, superplasticizers.

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45

Fry, Donald L. "Arterial intimal-medial permeability and coevolving structural responses to defined shear-stress exposures." American Journal of Physiology-Heart and Circulatory Physiology 283, no. 6 (December 1, 2002): H2341—H2355. http://dx.doi.org/10.1152/ajpheart.00219.2001.

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The purpose of this research was to examine the evolution of arterial shear stress-induced intimal albumin permeability and coevolving structural responses in swine arteries. Uniform laminar shear-stress responses were compared with those of a simulated “flow separation” stress field. These fields were created using specially designed flow-configuring devices in an experimentally controlled, metabolically supported, ex vivo thoracoabdominal aorta preparation. The Evans blue dye-albumin complex (EBD-alb) permeability patterns that evolved were measured by a reflectometric method. The corresponding tissue structural responses were evaluated by histological, immunostaining, and ultrastructural microscopic techniques. It was shown that when a previously in vivo-adapted artery is challenged by a new mechanochemical environment, it undergoes a sequence of adaptive processes over the ensuing 95 h. Intimal regions of laminar shear-stress exposure (∼16 dyn/cm2) responded initially (23 h) with an increase in permeability. With continued stress exposure, intimal-medial structural changes ensued that restored the artery to a physiologically normal permeability. Over this same period, adjacent endothelial regions exposed to simulated flow separation stress fields (∼0.03–0.27 dyn/cm2) developed early and progressively increasing permeability. This was associated with formation of local intimal edema, loss of intimal matrix material, and development of distinctively raised, gelatinous-appearing intimal lesions having a potentially preatheromatous architecture.

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46

Wang, Liyan, Jiatao Yan, Qi Wang, Binghui Wang, and Aimable Ishimwe. "Study on Permeability of Steel Slag and Steel Slag Modifying Silt Soil as New Geo-Backfill Materials." Advances in Civil Engineering 2019 (July 1, 2019): 1–14. http://dx.doi.org/10.1155/2019/5370748.

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To make steel slag being reasonably used in geotechnical backfilling projects or soft foundation treatment projects, three kinds of steel slag such as fine, coarse, and gravel steel slag were studied through particle analysis tests, relative density tests, and specific gravity tests to obtain basic physical parameters. Considering the influence of relative density, gradation, and other factors, constant head permeability tests of pure steel slag and variable head permeability tests of modified silt soil with different mixing contents of steel slag were carried out to test permeability coefficients under various working conditions. Prediction formulas on the permeability coefficients of the three kinds of pure steel slag and steel slag-treated silt soil were, respectively, deduced. It was concluded that the permeability coefficient of pure steel slag was greatly influenced by particle size and relative density, similar to the case of permeability coefficients of fly ash and fine sand in their dense states, and the larger the relative density was, the smaller the permeability coefficient was. The permeability coefficient of steel slag-treated silt soil increased with increasing of mixing content of steel slag, showing that steel slag can obviously improve the permeability performance of silt soil. Research results provide reference for design and construction on the application of steel slag in roadbed backfill, steel slag modifying silt soil, and other projects.

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Ma, Zhiming, Guangzhong Ba, and Zhenhua Duan. "Effects of High Temperature and Cooling Pattern on the Chloride Permeability of Concrete." Advances in Civil Engineering 2019 (January 13, 2019): 1–13. http://dx.doi.org/10.1155/2019/2465940.

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Concrete structure is frequently subjected to the fire attack, whereas the permeability of concrete with fire-damage has received little consideration. This paper aims to investigate the chloride permeability of plain concrete and recycled aggregate concrete (RAC) with fire-damage, and the effects of various cooling patterns and recuring treatment on the chloride permeability are also studied. The results manifest that the elevated temperatures result in an increase in the fire-damage and chloride permeability of concrete, and that the increase becomes more obvious with the temperature above 400°C. Attributing to the water-cooling which provides a recuring environment, the chloride permeability after water-cooling is lower than that after air-cooling when the temperature is 200°C. Whereas when the temperature is above 400°C, the chloride permeability after water-cooling becomes higher than that after air-cooling, due to an extra damage that the water-cooling produces. The recuring treatment can reduce the chloride permeability of concrete with fire-damage, and the reduction becomes more significant when the concrete suffers a serious fire-damage. Exposing to the same condition of high temperature, the addition of recycled aggregate (RA) further boosts the fire-damage and chloride permeability of concrete. Particularly, the chloride permeability increases with the increasing of RA replacement ratios, linearly, and the increased temperatures further lead to an increase in the slope of the fitting straight line.

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48

Yang, Rong, Zengguang Xu, and Junrui Chai. "Seepage Analysis of a Multilayer Waste Slope considering the Spatial and Temporal Domains of Permeability." Advances in Civil Engineering 2019 (August 25, 2019): 1–10. http://dx.doi.org/10.1155/2019/3689097.

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Landfilled municipal solid waste has evident heterogeneity, and clogging of the drainage layer can easily happen during operation of the landfill. These two factors significantly influence the distribution of leachate in a landfill. Herein, the distribution of waste permeability in the spatial and temporal domains was analyzed. Then, changes to the drainage-layer permeability in the temporal domain were fitted to these data. A simple model of multilayer waste slope was established combining the finite element software and a user subroutine. Herewith, changes of permeability in the waste and drainage layers were simulated, such that the heterogeneity of waste and the process of clogging of the drainage layer could be simulated. Then, the leachate distributions and transport conditions of nine schemes for landfill were analyzed. The results indicated that the distribution curve of waste-saturated permeability follows a logarithmic relation in the vertical direction, and the distribution curve of fresh-waste-saturated permeability follows a polynomial relation in time. After each landfill is worked for a few years, the drainage layer always encounters clogging problems of some kind and its permeability decreases by one to five orders of magnitude. Through numerical models, the simulation results of the permeability distribution in the spatial and temporal domains were found satisfactory. When the permeability distributions were layered in the buried depth, pore pressures and leachate levels are smaller than the logarithmic distributions. During the process of degradation, the pore pressures and leachate levels are increased slightly under the consideration of the polynomial distribution of waste permeability in time. With clogging of the permeability of the drainage layer, the pore pressures and leachate levels of landfill were found to be increasing gradually. To obtain results closer to that of actual situations, corresponding models should be established and analyzed based on a range of permeability, waste degradation rate, and degree of clogging.

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49

Dublineau, I., F. Lebrun, S. Grison, and N. M. Griffiths. "Functional and structural alterations of epithelial barrier properties of rat ileum following X-irradiation." Canadian Journal of Physiology and Pharmacology 82, no. 2 (February 1, 2004): 84–93. http://dx.doi.org/10.1139/y03-129.

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Irradiation of the digestive system leads to alterations of the small intestine. We have characterized the disruption of the barrier integrity in rat ileum from 1 to 14 days following irradiation ranging from 6 to 12 Gy. The intestinal permeability to 14C-mannitol and 3H-dextran 70 000 was measured in vitro in Ussing chambers. In parallel to these functional studies, immunohistochemical analyses of junctional proteins (ZO-1 and β-catenin) of ileal epithelium were performed by confocal microscopy. Irradiation with 10 Gy induced a marked decrease in epithelial tissue resistance at three days and a fivefold increase in mannitol permeability, without modifications of dextran permeability. A disorganization of the localization for ZO-1 and β-catenin was also observed. At 7 days after irradiation, we observed a recovery of the organization of junctional proteins in parallel to a return of intestinal permeability to control value. In addition to these time-dependent effects, a gradual effect on epithelial integrity of the radiation doses was observed 3 days after irradiation. This study shows a disruption of the integrity of the intestinal barrier in rat ileum following abdominal X-irradiation, depending on the time postirradiation and on the delivered dose. The loss of barrier integrity was characterized by a disorganization of proteins of tight and adherent junctions, leading to increased intestinal permeability to mannitol.Key words: intestinal permeability, ZO-1, β-catenin, tight and adherent junctions.

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50

Spasojevic, M., L. Ribic-Zelenovic, N. Cirovic, P. Spasojevic, and A. Maricic. "Effect of milling and annealing on microstructural, electrical and magnetic properties of electrodeposited Ni-11.3 Fe-1.4w alloy." Science of Sintering 44, no. 2 (2012): 197–210. http://dx.doi.org/10.2298/sos1202197s.

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A nanostructured Ni-11.3Fe-1.4W alloy deposit was obtained from an ammonium citrate bath at a current density of 600 mAcm-2. XRD analysis shows that the deposit contains an amorphous matrix having embedded nanocrystals of the FCC phase of the solid solution of Fe and W in Ni with the average crystal grain size of 8.8 nm. The deposit has a high internal microstrain value and a high minimum density of chaotically distributed dislocations. The effect of milling and annealing of the Ni-11.3Fe-1.4W alloy on electrical and magnetic properties was studied. Structural changes in the alloy take place during both annealing and milling. Upon deposition, the alloy was heated to 420?C. Heating resulted in structural relaxation which induced a decrease in electrical resistivity and an increase in magnetic permeability of the alloy. Further heating of the alloy at temperatures higher than 4200C led to crystallization which caused a reduction in both electrical resistivity and magnetic permeability. The milling of the alloy for up to 12 hours caused a certain degree of structural relaxation and crystallization of the alloy. The increase in crystal grain size up to 11 nm and the partial structural relaxation induced a decrease in electrical resistivity and an increase in magnetic permeability of the alloy. Heating the powders obtained by milling at 4200C led to complete structural relaxation, reduced electrical resistivity, and increased magnetic permeability. During heating of the powders obtained by milling at temperatures above 420?C, crystallization and a significant increase in crystal grain size occurred, leading to a reduction in both electrical resistivity and magnetic permeability. The best magnetic properties were exhibited by the alloys milled for 12 hours and annealed thereafter at 420?C. In these alloys, crystal grains were found to have an optimum size, and complete relaxation took place, resulting in a maximum increase in magnetic permeability.

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Journal articles on the topic 'Structural permeability'

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