INFLUENCE OF RANDOM AGGREGATES ON DIFFUSION BEHAVIOR OF CHLORIDE IONS IN CONCRETE BASED ON COMSOL SIMULATION

Nowadays, influences of concrete cracking on durability of concrete structure are widely reported. However, the influence of macro cracks on chloride diffusion of concrete is unknown under the condition of marine submergence. Therefore, the present paper adopted a notch method to study natural chloride diffusion in cracked concrete with a width of above 0.3 mm. The results show Apparent diffusion coefficient of acid soluble chloride rises from 2.66 ×10-12 m2/s to 5.92×10-12 m2/s with increasing crack width from 0 mm to 0.45 mm. Besides, one exponential function was used to describe the piecewise relationship between diffusion coefficient (water or acid soluble chloride) and crack width.

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Author's reply to discussion of paper “diffusion behavior of chloride ions in concrete” by S. Chatterji

Cement and Concrete Research ◽

10.1016/s0008-8846(96)00189-5 ◽

1997 ◽

Vol 27 (1) ◽

pp. 159

Keyword(s):

Chloride Ions ◽

Diffusion Behavior

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Simulating chloride penetration in fly ash concrete by a fractal derivative model

Thermal Science ◽

10.2298/tsci181024331q ◽

2019 ◽

Vol 23 (Suppl. 1) ◽

pp. 67-78 ◽

Cited By ~ 1

Author(s):

Pengfei Qu ◽

Xiaoting Liu ◽

Dumitru Baleanu

Keyword(s):

Fractional Derivative ◽

Linear Regression Analysis ◽

Chemical Properties ◽

Mathematical Expression ◽

Fractal Model ◽

Chloride Ions ◽

Diffusion Behavior ◽

Fractional Derivative Model ◽

Fractal Derivative ◽

Diffusion Phenomena

In the real engineering field, the chloride ions behave abnormal diffusion phenomena in concrete caused by different compositions of the concrete which lead to the complex physical and chemical properties. This paper utilizes a fractal derivative model and a fractional derivative model to describe the diffusion phenomena. Furthermore, according to actual experimental data in the field, the fractional and fractal model can simulate the diffusion behavior of chloride ions in concrete. In comparison to the fractional derivative model, the fractal derivative model gives a simpler mathematical expression and lower calculation costs. In addition, the linear regression analysis method is used to establish an effective relationship between the internal composition of concrete and the parameters of fractal model such as fractal order, ?, and diffusion coefficient, D. As a result, the fractal model with the parameters estimated by previous relationship can predict the diffusion behavior of chloride ions.

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Junction of the Epithelium and Lamina Propria of the Bovine Rumen Mucosa

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100060350 ◽

1967 ◽

Vol 25 ◽

pp. 68-69

Author(s):

Al W. Stinson

Keyword(s):

Osmium Tetroxide ◽

Squamous Epithelium ◽

Short Chain Fatty Acids ◽

Chloride Ions ◽

Fermentation Products ◽

Ruminant Species ◽

Protective Shield ◽

Stratified Squamous Epithelium ◽

Lead Hydroxide ◽

Acetic Acids

The stratified squamous epithelium which lines the ruminal compartment of the bovine stomach performs at least three important functions. (1) The upper keratinized layer forms a protective shield against the rough, fibrous, constantly moving ingesta. (2) It is an organ of absorption since a number of substances are absorbed directly through the epithelium. These include short chain fatty acids, potassium, sodium and chloride ions, water, and many others. (3) The cells of the deeper layers metabolize butyric acid and to a lesser extent propionic and acetic acids which are the fermentation products of rumen digestion. Because of the functional characteristics, this epithelium is important in the digestive process of ruminant species which convert large quantities of rough, fibrous feed into energy.Tissue used in this study was obtained by biopsy through a rumen fistula from clinically healthy, yearling holstein steers. The animals had been fed a typical diet of hay and grain and the ruminal papillae were fully developed. The tissue was immediately immersed in 1% osmium tetroxide buffered to a pH of 7.4 and fixed for 2 hrs. The tissue blocks were embedded in Vestapol-W, sectioned with a Porter-Blum microtome with glass knives and stained with lead hydroxide. The sections were studied with an RCA EMU 3F electron microscope.

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Factors Influencing the Separation of Glu-Plasminogen Affinity Forms I and II by Affinity Chromatography

Thrombosis and Haemostasis ◽

10.1055/s-0038-1661211 ◽

1984 ◽

Vol 52 (03) ◽

pp. 347-349 ◽

Cited By ~ 6

Author(s):

Daan W Traas ◽

Bep Hoegee-de Nobel ◽

Willem Nieuwenhuizen

Keyword(s):

Affinity Chromatography ◽

Dissociation Constants ◽

Ionic Composition ◽

Chloride Ions ◽

Factors Influencing ◽

Two Factors ◽

Human Plasminogen

SummaryNative human plasminogen, the proenzyme of plasmin (E. C. 3.4.21.7) occurs in blood in two well defined forms, affinity forms I and II. In this paper, the feasibility of separating these forms of human native plasminogen by affinity chromatography, is shown to be dependent on two factors: 1) the ionic composition of the buffer containing the displacing agent: buffers of varying contents of sodium, Tris, phosphate and chloride ions were compared, and 2) the type of adsorbent. Two adsorbents were compared: Sepharose-lysine and Sepharose-bisoxirane-lysine. Only in the phosphate containing buffers, irrespective of the type of adsorbent, the affinity forms can be separated. The influence of the adsorbent can be accounted for by a large difference in dissociation constants of the complex between plasminogen and the immobilized lysine.

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