scholarly journals Permeability of Concrete and Correlation with Microstructure Parameters Determined by 1H NMR

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Yurong Zhang ◽  
Shengxuan Xu ◽  
Zhaofeng Fang ◽  
Junzhi Zhang ◽  
Chaojun Mao
Keyword(s):  
Water Permeability ◽  
Permeability Coefficient ◽  
Pore Diameter ◽  
Gas Permeability ◽  
Steady State Flow ◽  
Test Device ◽  
Water Permeability Coefficient ◽  
Microstructure Parameters ◽  
The Relationship ◽  
Better Than

Water and gas permeability coefficients of concrete with different water-binder (w/b) ratios and admixtures were measured by a self-designed test device based on the steady-state flow method for liquid and the method of differential pressure in stability for gas, respectively. In addition, the micropore structure of concrete was determined by 1H nuclear magnetic resonance (NMR). Results indicated that there are good correlations between water and gas permeability of concrete with different w/b ratios, with correlation coefficient greater than 0.90. Better correlations between water permeability and segmental contributive porosity ranged from 10 to 100 nm and 100 to 1000 nm can be identified, but the gas permeability is more relevant to the segmental contributive porosity ranging from 100 to 1000 nm. Moreover, the correlation between water permeability and contributive porosity for each pore diameter is always better than that of gas permeability. The influence of admixtures on the relationship between permeability and pore size distribution of concrete is significant. Moreover, water permeability coefficient is one or two orders of magnitude lower than the gas permeability coefficient.

Research on a New Method of Evaluating Compaction of Pavement

2013 ◽  
Vol 723 ◽  
pp. 171-176
Author(s):  
Fei Chen ◽  
Ming Chen
Keyword(s):  
Surface Temperature ◽  
Water Permeability ◽  
Permeability Coefficient ◽  
Asphalt Pavement ◽  
New Method ◽  
Water Permeability Coefficient ◽  
Infra Red ◽  
Set Up ◽  
Water Saturated ◽  
The Relationship

in this paper the surface temperature of test specimens which were water-saturated were measured after different exposure time in the lamplight. The relationship can be set up among surface temperature,air viods and water permeability coefficient. This research demonstrated that there is good correlation. So when the pavement is in the sunshine for a time after a rain,asphalt pavement areas with different water permeability coefficient can be distinguished by using infra-red technology to measure the surface temperature.Compaction of asphalt pavement can also be evaluated. This way was used and checked up in shanghai-chengdu highway project. This is a new method what is very convinently and quickly to evaluate the compaction and homogeneity of asphalt pavement.

scholarly journals Impact of Biochar on Soil Water Permeability Coefficient During 2 Year Field Experiment

2020 ◽  
Vol 609 ◽  
pp. 012108
Author(s):  
Maciej Gliniak ◽  
Jakub Sikora ◽  
Urszula Sadowska ◽  
Agnieszka Klimek-Kopyra ◽  
Agnieszka Latawiec ◽  
...  
Keyword(s):  
Field Experiment ◽  
Soil Water ◽  
Water Permeability ◽  
Permeability Coefficient ◽  
Water Permeability Coefficient

Cell osmotic water permeability of isolated rabbit proximal straight tubules

1982 ◽  
Vol 242 (4) ◽  
pp. F321-F330 ◽  
Author(s):  
E. Gonzalez ◽  
P. Carpi-Medina ◽  
G. Whittembury
Keyword(s):  
Surface Area ◽  
Water Flow ◽  
Water Permeability ◽  
Permeability Coefficient ◽  
Osmotic Water Permeability ◽  
Water Permeability Coefficient ◽  
Osmotic Water ◽  
Straight Tubules ◽  
Tubular Surface ◽  
Set Up

Proximal straight tubules were dissected and mounted in a chamber with their lumina occluded. The well-stirred bath could be 95% changed within 84 ms to set up osmotic gradients (delta Coi) across the peritubular cell aspect. Volume changes (less than or equal to 10 pl/mm) were estimated from continuous records of diameter changes (error less than 0.1 micrometers). delta Coi greater than or equal to 2-3 mosM could be discerned. delta Coi values from 10 to 44 mosM were used to evaluate Posc, the cell osmotic water permeability coefficient, and extrapolated to delta Coi = 0. Posc = 25.1 (+/- 2.3) X 10(-4) cm3.s-1.osM-1.cm2 tubular surface area-1. These values are lower than those reported for Pose, the transepithelial osmotic water permeability coefficient, and become lower if corrected for the real (infolded) peritubular cell surface area. Thus, for a given osmotic difference, transcellular water flow finds a higher resistance than paracellular water flow. Experiments were also performed with delta Coi greater than 100 mosM, but interpretation of these data is difficult because of the presence of volume regulatory phenomena and other undesirable effects.

Mechanisms and regulation of water permeability in renal epithelia

1989 ◽  
Vol 257 (5) ◽  
pp. C837-C850 ◽  
Author(s):  
A. S. Verkman
Keyword(s):  
Urinary Bladder ◽  
Proximal Tubule ◽  
Water Permeability ◽  
Permeability Coefficient ◽  
Biological Membranes ◽  
Water Channels ◽  
Proton Pumps ◽  
Toad Urinary Bladder ◽  
Water Permeability Coefficient ◽  
Collecting Tubule

Water transport occurs in all biological membranes. A few selected membranes in the kidney, amphibian urinary bladder, and erythrocyte have very high water permeability and are thought to contain specialized water transporting units termed "water channels." The known biophysical properties of membranes containing water channels are a high osmotic water permeability coefficient (Pf), an osmotic-to-diffusional water permeability coefficient ratio (Pf/Pd) greater than unity, a low activation energy (Ea), and inhibition by mercurial compounds. The biochemical and molecular characteristics of water channel pathways are not known at present. Established and new methods to measure Pf and Pd in kidney tubules and in isolated membrane vesicles from kidney cells are reviewed and evaluated. In the mammalian proximal tubule, a high Pf results from transcellular movement of water across highly permeable apical and basolateral membranes containing water channels. It has been assumed that proximal tubule Pf is unregulated; however, recent results indicate that apical water channels are retrieved by endocytosis and that Pf is decreased fivefold with increasing transepithelial osmotic gradients. In the thin and thick ascending limbs, Pf is nearly the lowest of all biological membranes and is not subject to regulation. In contrast, collecting tubule Pf is subject to hormonal regulation by vasopressin. Vasopressin binding to receptors located at the basal membrane of principal cells initiates adenosine 3',5'-cyclic monophosphate production, which is thought ultimately to activate the exocytic insertion of intracellular vesicles containing water channels into the cell apical membrane. Vasopressin-induced endosomes from kidney collecting tubule and toad urinary bladder contain functional water channels but no proton pumps or urea transporters, supporting a membrane shuttle hypothesis that is selective for water channels. Future directions for the isolation and molecular cloning of kidney water channels are evaluated.

Diffusion and Permeation of Water in the Frog Egg: The Effect of Tension and Tonicity

1974 ◽  
Vol 61 (3) ◽  
pp. 697-703
Author(s):  
KJELL HANSSON MILD ◽  
SØREN LØVTRUP
Keyword(s):  
Plasma Membrane ◽  
Water Permeability ◽  
Incubation Time ◽  
Permeability Coefficient ◽  
External Medium ◽  
Body Cavity ◽  
Vitelline Membrane ◽  
Unstirred Layers ◽  
Water Permeability Coefficient ◽  
Isotopic Water

1. The isotopic water permeability coefficient, P, of the plasma membrane of frog body cavity eggs has been determined as a function of the incubation time in media of different tonicity. 2. It was found that the permeability decreases with the incubation time in hypotonic solutions. The observed changes may be correlated with an increase of the tension in the vitelline membrane. 3. In the evaluation of the experimental results the diffusion of water in the external medium (‘unstirred layers’) is taken into account.

scholarly journals Experimental Study of the Independence of Diffusion and Hydrodynamic Permeability Coefficients in Collodion Membranes

1960 ◽  
Vol 43 (3) ◽  
pp. 523-532 ◽  
Author(s):  
Elliott Robbins ◽  
Alexander Mauro
Keyword(s):  
Experimental Study ◽  
Permeability Coefficient ◽  
Pore Diameter ◽  
Irreversible Thermodynamics ◽  
Average Pore Diameter ◽  
Average Pore ◽  
Flux Data ◽  
Two Parameters ◽  
The Relationship ◽  
Hydrodynamic Permeability

The two parameters usually invoked when discussing transport across membranes are the "diffusion permeability coefficient" and the "hydrodynamic permeability coefficient." In this study the magnitude of these two coefficients is established experimentally for collodion membranes of differing porosities. The hydrodynamic permeability is predominant while convergence of the two permeabilities tends to obtain as the membranes become less coarse. The flux data obtained are used to calculate "average pore diameter" and the meaningfulness of these calculations is interpreted. The relationship between the two coefficients and transport across membranes as treated by the system of irreversible thermodynamics is discussed.

scholarly journals Nature of the water permeability increase induced by antidiuretic hormone (ADH) in toad urinary bladder and related tissues.

1976 ◽  
Vol 68 (2) ◽  
pp. 137-143 ◽  
Author(s):  
A Finkelstein
Keyword(s):  
Urinary Bladder ◽  
Cell Membrane ◽  
Antidiuretic Hormone ◽  
Lipid Bilayers ◽  
Water Permeability ◽  
Permeability Coefficient ◽  
Diffusion Mechanism ◽  
Toad Urinary Bladder ◽  
Lipid Bilayer Membranes ◽  
Water Permeability Coefficient

In artificial lipid bilayer membranes, the ratio of the water permeability coefficient (Pd(water)) to the permeability coefficient of an arbitrary nonelectrolyte such as n-butyramide (Pd(n-butyramide)) remains relatively constant with changes in lipid composition and temperature, even though the individual Pd's increase more than 100-fold. I propose that this is a general rule that also holds for the lipid bilayers of cells and tissues, and that therefore if Pd(water)/Pd(solute greatly exceeds the value found for artifical lipid bilayers (where "solute" is a molecule, such as 1,6 hexanediol or n-butyramide, that crosses the cell membrane by a solubility-diffusion mechanism without the aid of a special transporting system), then water crosses the cell membrane via aqueous pores. Applying this criterion to the toad urinary bladder, we find that even in the unstimulated bladder, water probably crosses the luminal membrane primarily through small aqueous pores, and that this almost certainly the case after antidiuretic hormone (ADH) stimulation. I suggest that ADH stimulation ultimately leads either to formation (or enlargement) of pores, by the rearrangement of preexisting subunits, or to an unplugging of these pores.

Parameters influencing water permeability coefficient of cracked concrete specimens

2017 ◽  
Vol 151 ◽  
pp. 907-915 ◽  
Author(s):  
Kyung Joon Shin ◽  
Wonho Bae ◽  
Seul-Woo Choi ◽  
Min Woo Son ◽  
Kwang Myong Lee
Keyword(s):  
Water Permeability ◽  
Permeability Coefficient ◽  
Cracked Concrete ◽  
Water Permeability Coefficient
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