On the Relationship between Deteriorated Level of ASR Damaged Concrete and Lithium Migration from Acceleration Lithium Migration Technique Test

2010 ◽  
Vol 163-167 ◽  
pp. 3812-3819
Author(s):  
Wei Chien Wang ◽  
Chih Chien Liu ◽  
Chau Lee
Keyword(s):  
Steady State ◽  
Linear Relationship ◽  
Current Density ◽  
Lithium Ion ◽  
Sodium Ion ◽  
Electrochemical Technique ◽  
The Relationship ◽  
Lithium Migration ◽  
Migration Technique

This research is to study the effect of deteriorated level on the ions migration in inhibiting the concrete damaged by ASR using electrochemical technique. Cylindrical concrete specimens made by reactive sandstone with 10 cm diameter and 5 cm height were prepared at the ages of 7, 14, 28, 90, and 180 days curing in a 38°C and 100% R.H. storage environment. The accelerated lithium migration technique (ALMT) was performed using LiOH H2O and Ca(OH)2 as electrolytes for anode and cathode, respectively. 9 A/m2 current density was used to drive lithium ion into and remove sodium ion out of the concrete. The results show that the rates of ions migration increase with increasing the deteriorated level of specimen. Furthermore, a linear relationship exists between the non-steady state migration coefficient of Li+ and the deteriorated level of specimen.

Influence of Aggregate Volume Ratio of Mortar on the Migration of Cations Using the Accelerated Lithium Migration Technique

2011 ◽  
Vol 230-232 ◽  
pp. 400-404
Author(s):  
Wei Chien Wang ◽  
Chih Chien Liu ◽  
Chau Lee
Keyword(s):  
Steady State ◽  
Current Density ◽  
Linear Correlation ◽  
Volume Ratio ◽  
Constant Current ◽  
Constant Current Density ◽  
Pass Through ◽  
And Migration ◽  
Lithium Migration ◽  
Migration Technique

This study utilizes mortar specimens, to design 3 different a/c ratios of 2.25, 2.75, and 3.25. The aggregate volume ratios (Vf) are 46 %, 52 %, and 57 %, respectively, while the w/c ratio is 0.5, and undergoing a 9, 12, and 15 A/m2 constant current density Accelerated Lithium Migration Technique after curing for 3 months. Results show that, on specimens applied with the same current density, the time of Li+ to pass through the specimen, and steady state flux and migration coefficient all exhibit a positive linear correlation with Vf. At the same time, the non-steady state migration coefficient for Li+ have a negative linear correlation with Vf.

The Rate of Change of Mouth Occlusion Pressure during Exercise

1979 ◽  
Vol 56 (5) ◽  
pp. 455-461 ◽  
Author(s):  
N. Siafakas ◽  
A. J. R. Morris ◽  
F. J. Prime
Keyword(s):  
Steady State ◽  
Linear Relationship ◽  
Regression Line ◽  
Constant Load ◽  
Rate Of Change ◽  
Significant Linear Relationship ◽  
Progressive Exercise ◽  
The Difference ◽  
Mouth Occlusion Pressure ◽  
The Relationship

1. The initial rate of change of pressure at the mouth (dP/dt) during a brief occlusion of the airways at the beginning of inspiration has been estimated in nine healthy subjects at rest, during exercise and during the first 2 min of recovery. Exercise was carried out with progressively increasing loads to the maximum tolerated (progressive exercise) and also for a period of 6 min at a constant load of 60% of the maximum (steady-state exercise). 2. A highly significant linear relationship was found between work loads and dP/dt during progressive exercise in all our subjects. 3. A highly significant linear relationship was found between ventilation and dP/dt in both forms of exercise, but the slope of the regression line was steeper during progressive than during steady-state exercise in six out of nine subjects. 4. The pattern of breathing (VT, f, VT/Tinsp., Tinsp./Ttot.) did not account for the difference in the relationship between dP/dt and ventilation during the two forms of exercise. 5. These results are in agreement with the hypothesis that dP/dt is an index of central inspiratory drive.

Effect of the Interfacial Transition Zone on the Migration Behavior of Cations under the Accelerated Lithium Migration Technique

2011 ◽  
Vol 250-253 ◽  
pp. 3743-3747
Author(s):  
Chih Chien Liu ◽  
Wei Chien Wang
Keyword(s):  
Regression Analysis ◽  
Steady State ◽  
Transition Zone ◽  
Interfacial Transition Zone ◽  
Combined Effect ◽  
Migration Behavior ◽  
Volume Fractions ◽  
The Matrix ◽  
Lithium Migration ◽  
Migration Technique

This paper researches the effect of the interfacial transition zone (ITZ) on the migration behavior of cations under the Accelerated Lithium Migration Technique (ALMT). Cylindrical mortars with different aggregate volume fractions (Vf) and w/c=0.5 were used. The result shows that when Vf≤ 20 %, the Li+steady state migration coefficient (Ds) is influenced by the dilution and tortuosity effects of the aggregate. The combined effect of ITZ and percolation occurs at Vf= 30 %, and the effects increase with the increase in Vf. Based on the experimental and regression analysis results, when the assumed thickness of ITZ = 20 μm, the approximate Dsof ITZ and percolated ITZ are 46.4 and 52.6 times the matrix migration coefficient.

Migration of Cations in Mortar under an Electrical Field Controlled by a Constant Current Density

2010 ◽  
Vol 150-151 ◽  
pp. 362-372 ◽  
Author(s):  
Wei Chien Wang ◽  
Chih Chien Liu ◽  
Chau Lee
Keyword(s):  
Current Density ◽  
Constant Current ◽  
Alkali Silica Reaction ◽  
Test Cases ◽  
Applied Current ◽  
Electrical Field ◽  
Constant Current Density ◽  
And Migration ◽  
Lithium Migration ◽  
Migration Technique

In this study, an Accelerated Lithium Migration Technique (ALMT) was applied to simultaneously drive alkali out and lithium into concrete as a remedy for alkali-silica reaction (ASR) problem. The mortar specimens used in the experiments contained 2.0% Na2Oeq. Constant current denities were applied during the ALMT testing process. The anolyte and catholyte solutions consisted of LiOH．H2O and Ca(OH)2, respectively. The results show that there are a well correlated linear relationship between the applied current density and the steady flux and migration coefficient of the Li+. During the process of ionic migration, K+ was first removed completely from the specimen, followed by Na+, after which the Li+ flux remained steady. The system resistance initially decreased, and then increased gradually. The time corresponding to when the Li+ concentration in the cathode/Li+ in the source cell was equal to 0.1% indicates the time-span needed for Li+ to penetrate throughout the specimen. Furthermore, the accumulated charge carried by the cations and the accumulated charge applied during testing showed a similar in all test cases.

N-Doped 3D Interconnected Carbon Bubbles as Anode Materials for Lithium-Ion and Sodium-Ion Storage with Excellent Performance

2019 ◽  
Vol 19 (11) ◽  
pp. 7301-7307 ◽  
Author(s):  
Biwu Wang ◽  
Zhuang Li ◽  
Jingjing Zhang ◽  
Zhigang Xia ◽  
Hua Yang ◽  
...  
Keyword(s):  
Lithium Ion Batteries ◽  
Current Density ◽  
Active Sites ◽  
Lithium Ion ◽  
Sodium Ion ◽  
Acid Extraction ◽  
Sodium Ion Batteries ◽  
Ion Storage ◽  
Sodium Ion Storage ◽  
A Current

In this paper, we develop a novel N-doped 3D interconnected carbon bubbles (NCBs) by a facile method of nitric acid extraction precursor at room temperature for the lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs). The NCBs with hollow carbon bubbles having a size of ~100 nm interconnected to each other exhibits high specific surface area and abundant active sites, which ensures continuous diffusion paths for ions and electrons and keeps the electrode structure more stable, thus significantly enhancing the lithium-ion and sodium-ion storage capability. In lithium-ion batteries, the NCBs electrode shows a high reversible capacity of 1180 mA h g−1 after 380 cycles at a current density of 1 C. As the current density increased from 1 to 10 C, the capacity still retains 407.1 mA h g−1. While in sodium-ion batteries, the NCBs electrode provides a capacity of 222.5 mA h g−1 after 200 cycles at a current density of 50 mA g−1. And the capacity maintains at 107.5 mA h g−1 even the current density increased from 0.05 to 5 A g−1. The excellent cycling performance and high-rate capability should be attributed to the synergistic effect of the 3D interconnected hollow structure and the incorporation of nitrogen atoms.

CuS2 sheets: a hidden anode material with a high capacity for sodium-ion batteries

2021 ◽  
Author(s):  
Shaohua Lu ◽  
Weidong Hu ◽  
Xiaojun Hu
Keyword(s):  
Lithium Ion Batteries ◽  
Anode Material ◽  
Low Cost ◽  
High Capacity ◽  
Lithium Ion ◽  
Sodium Ion ◽  
Sodium Ion Batteries

Due to their low cost and improved safety compared to lithium-ion batteries, sodium-ion batteries have attracted worldwide attention in recent decades.

Mast Cells as a Double-Edged Sword in Immunity: Their Function in Health and Disease. First of Two Parts

2020 ◽  
Vol 20 (5) ◽  
pp. 654-669
Author(s):  
Thea Magrone ◽  
Manrico Magrone ◽  
Emilio Jirillo
Keyword(s):  
Steady State ◽  
Mast Cells ◽  
Immune Cells ◽  
Food Antigens ◽  
Health And Disease ◽  
The Relationship

Mast cells (MCs) have recently been re-interpreted in the context of the immune scenario in the sense that their pro-allergic role is no longer exclusive. In fact, MCs even in steady state conditions maintain homeostatic functions, producing mediators and intensively cross-talking with other immune cells. Here, emphasis will be placed on the array of receptors expressed by MCs and the variety of cytokines they produce. Then, the bulk of data discussed will provide readers with a wealth of information on the dual ability of MCs not only to defend but also to offend the host. This double attitude of MCs relies on many variables, such as their subsets, tissues of residency and type of stimuli ranging from microbes to allergens and food antigens. Finally, the relationship between MCs with basophils and eosinophils will be discussed.

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