scholarly journals Effects of Aging on the Dry Shrinkage Cracking of Lime Soils with Different Proportions

2021 ◽  
Vol 12 (1) ◽  
pp. 145
Author(s):  
Jianwei Yue ◽  
Ying Chen ◽  
Limin Zhao ◽  
Siyuan Wang ◽  
Huicong Su ◽  
...  
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Aging Time ◽  
Particle Structure ◽  
Shrinkage Cracking ◽  
Lime Content ◽  
Internal Mechanism ◽  
Dry Shrinkage ◽  
Effects Of Aging ◽  
Aging Stage

In this study, the reasonable aging time of lime soils with different ratios was determined to investigate the effect of aging on the internal mechanism of the dry shrinkage cracking of lime soil. To this end, the effects of aging time, lime content, and particle size on the volume crack rate, expansion and shrinkage rate, particle size distribution, and pH were analyzed using a dry–wet cycle, screening, and pH tests. In addition, the changes in the particle structure of the samples and the formation of new substances were analyzed. The results revealed that the volume crack and expansion shrinkage rates of the sample initially decreased, and then stabilized with increasing aging time. In addition, the aging time of the sample increased with increasing lime content and particle size. Further, at the initial aging stage, the volume crack and expansion/shrinkage rates of the sample increased with increasing lime content and particle size. With an increase in the aging time, the pH increased and then decreased significantly to 0.57–1.1% at the reasonable aging time. These indicate that the pH exhibited a significant effect on the reasonable aging time, and this will provide useful insights for the restoration of lime soil sites.

Effects of Hydrolysis Parameters on TiO2 White Pigment from Low Concentration Industrial TiOSO4 Solution via Sulfate Process

2012 ◽  
Vol 602-604 ◽  
pp. 1243-1249 ◽  
Author(s):  
Cong Xue Tian
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Aging Time ◽  
Volume Ratio ◽  
Narrow Particle Size Distribution ◽  
Water Volume ◽  
White Pigment ◽  
Anatase Titania ◽  
Sulfate Process

Short sulfate process was developed to produce TiO2 white by using unconcentrated industrial TiOSO4 solution as raw material. Herein, anatase titania white pigment was prepared by self-generated seeded thermal hydrolysis route. The effects of hydrolysis parameters (such as pre-adding water volume ratio, F value and aging time) on the structure and pigment properties of the as-prepared samples were investigated. The samples were characterized by XRD, particle size distribution, SEM and pigment properties test. These factors influenced the number and quality of the hydrolysis nuclei, hydrolysis velocity, crystal growth rate and the particles aggregation, eventually determined its structure and pigment properties. The optimized pre-adding water volume ratio was of 0.18:1, the F value was of 1.95 and the aging time after turning-grey-color point was of 20~30 min, and the prepared TiO2 was with anatase phase, narrow particle size distribution and excellent pigment properties.

Effect of Hydrolysis on High-Purity TiO2 Size for PTC Thermistor

2012 ◽  
Vol 528 ◽  
pp. 160-163
Author(s):  
Zhi Qiang Luo ◽  
Jian Qiao Du
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Heating Rate ◽  
Aging Time ◽  
High Purity ◽  
Volume Ratio ◽  
Solution Concentration ◽  
Thermal Hydrolysis ◽  
Optimum Volume

The effect of self-generated seeded thermal hydrolysis factors, such as TiOSO4 solution concentration, grey aging time, volume ratio of TiOSO4 to pre-adding water, and heating rate on high-purity TiO2 size for PTC thermistor were studied. The samples were characterized by particle size distribution, and SEM. The results show that with increase of TiOSO4 solution concentration, the high-purity TiO2 size decrease gradually, but with increase of grey aging time and volume ratio of TiOSO4 to pre-adding water respectively, the high-purity TiO2 size also increase. The suitable TiOSO4 concentration is 160g/l, grey aging time is 15min, the optimum volume ratio of TiOSO4 to pre-adding water is 4.0:1 and heating rate should be 1.5°C/min.

Effects of Particle Size Distribution on Corrosion Rate of Carbon Steel in Soil

2020 ◽  
Vol 69 (4) ◽  
pp. 102-106
Author(s):  
Shota Ohki ◽  
Shingo Mineta ◽  
Mamoru Mizunuma ◽  
Soichi Oka ◽  
Masayuki Tsuda
Keyword(s):  
Particle Size ◽  
Carbon Steel ◽  
Corrosion Rate ◽  
Particle Size Distribution ◽  
Size Distribution

DENSE SPRAY CORRECTIONS FOR DIFFRACTION-BASED PARTICLE SIZE DISTRIBUTION MEASUREMENTS

1995 ◽  
Vol 5 (1) ◽  
pp. 75-87 ◽  
Author(s):  
Christine M. Woodall ◽  
James E. Peters ◽  
Richard O. Buckius
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution

Influence of Cementite Particle Size Distribution on Machinability and Tool Life of High Carbon Cr-bearing Steels

1998 ◽  
Vol 84 (5) ◽  
pp. 387-392 ◽  
Author(s):  
Takashi INOUE ◽  
Yuzo HOSOI ◽  
Koe NAKAJIMA ◽  
Hiroyuki TAKENAKA ◽  
Tomonori HANYUDA
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Tool Life ◽  
Cementite Particle ◽  
High Carbon ◽  
Bearing Steels

Study of the microstructure and particles of vanadium (III) oxide, vanadium (V) oxide and lithium aluminate powders

2020 ◽  
Vol 86 (1) ◽  
pp. 32-37
Author(s):  
Valeria A. Brodskaya ◽  
Oksana A. Molkova ◽  
Kira B. Zhogova ◽  
Inga V. Astakhova
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Vanadium Oxide ◽  
Size Distribution ◽  
Microstructural Analysis ◽  
Coherent Scattering ◽  
Powder Materials ◽  
Lithium Aluminate ◽  
Range Limit ◽  
Oxide Particles

Powder materials are widely used in the manufacture of electrochemical elements of thermal chemical sources of current. Electrochemical behavior of the powders depends on the shape and size of their particles. The results of the study of the microstructure and particles of the powders of vanadium (III), (V) oxides and lithium aluminate obtained by transmission electron and atomic force microscopy, X-ray diffraction and gas adsorption analyses are presented. It is found that the sizes of vanadium (III) and vanadium (V) oxide particles range within 70 – 600 and 40 – 350 nm, respectively. The size of the coherent-scattering regions of the vanadium oxide particles lies in the lower range limit which can be attributed to small size of the structural elements (crystallites). An average volumetric-surface diameter calculated on the basis of the surface specific area is close to the upper range limit which can be explained by the partial agglomeration of the powder particles. Unlike the vanadium oxide particles, the range of the particle size distribution of the lithium aluminate powder is narrower — 50 – 110 nm. The values of crystallite sizes are close to the maximum of the particle size distribution. Microstructural analysis showed that the particles in the samples of vanadium oxides have a rounded (V2O3) or elongated (V2O5) shape; whereas the particles of lithium aluminate powder exhibit lamellar structure. At the same time, for different batches of the same material, the particle size distribution is similar, which indicates the reproducibility of the technologies for their manufacture. The data obtained can be used to control the constancy of the particle size distribution of powder materials.

Sign in / Sign up

Export Citation Format

Share Document