• Journal of Korean Society on Water Environment
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• v.27 no.1
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• pp.115-119
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• 2011

The mobility of groundwater in the soil environment has an important role in the soil environment and absorption of plant. Therefore, studies on the mobility of groundwater considering the physical and chemical properties of soil is very important. In this study, movement of water due to change in soil particle size were observed by capillary rise. The height of the capillaries was measured according to capillary diameter, temperature and solution concentration. The inner diameter of each capillary itself is 0.012, 0.016, 0.024, 0.027 cm, and experiments were performed at $22^{\circ}C$. As a result, the height of the capillaries decreased with increasing capillary diameter, and the solution temperature but increased with increasing concentration. Changes in the height of the capillaries are interpreted to related with surface tension by the Young-Laplace equation. Also on the mobility of groundwater, the increase of water and soil temperatures can be significant factors caused by ion strength and global warming as well as pores in the soil particles. The results of this study is considered to provide the basic data on the behavior of groundwater in the soil environment.

• Tribology and Lubricants
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• v.38 no.5
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• pp.185-190
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• 2022

Among the operating limits of a heat pipe, the capillary limit is significantly affected by the characteristics of the wick, which is determined by the capillary performance. The major parameters for determining capillary performance are the maximum capillary pressure and the spreading characteristics that can be expected through the wick. A well-designed wick structure improves capillary performance and helps improve the stability of the heat pipe by enhancing the capillary limit. The capillary performance can be improved by forming a porous microstructure on the surface of the wick structure through surface modification techniques. In this study, a microstructure is formed on the surface of the wick by using a surface modification method (i.e., an electrochemical etching process). In the experiment, specimens are prepared using stainless-steel screen mesh wicks with various fabrication conditions. In addition, the spreading and capillary rise performances are observed with low-surface-tension fluid to quantify the capillary performance. In the experiments, the capillary performance, such as spreading characteristics, maximum capillary pressure, and capillary rise rate, improves in the specimens with microstructures formed through surface modification compared with the specimens without microstructures on the surface. The improved capillary performance can have a positive effect on the capillary limit of the heat pipe. It is believed that the surface microstructures can enhance the operational stability of heat pipes.

• Journal of the Korean Chemical Society
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• v.9 no.2
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• pp.110-112
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• 1965

The surface tension of liquid iodine was measured by differential capillary rise method at various temperatures above the melting point. A paraffin bath with mercury regulator was used to maintain constant temperature. The height of the meniscus of liquid iodine in the capillary tube was measured by a travelling microscope. The measured values of surface tensions at $125.0^{\circ},135.0^{\circ}, 145.0^{\circ}$ and $155.0^{\circ}$ were 36.88, 35.87, 34.83 and 34.04 dyne/cm, respectively. Calculated Eotvos constant from the surface tension, data. experimentally obtained, were consistent through the temperature range.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.4D
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• pp.377-386
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• 2010

This study was conducted to find out the characteristics of the expanded road embankment constructed by the lightweight air-mixed soil (slurry density $10kN/m^3$) for a short-term without any ground improvement. Compression strength, capillary rise height of the lightweight air-mixed soil and settlement behavior of soft ground were studied. Compression strengths of the specimens sampled at the site after 1 and 5 months of construction were all satisfied the required strength 500 kPa. However, it was not convinced the homogeneity construction, because the values of strength were depending on the sampled location. Also, strength difference between laboratory and site specimens were found about 19%, and thus it should be considered for mixing design. Capillary rise reached about 20 cm for 70 hours because of a numerous tiny pores existed inside the lightweight air-mixed soil. Relationship between settlement and time of the soft ground placed underneath the expanded embankment was estimated by using the measured data and back analysis technique. The current average consolidation ratio and the final settlement after 120 months later were estimated about 32% and 4.5cm, respectively. This settlement is much less value than the allowable settlement 10cm for this structure.

• Journal of the Korean Geotechnical Society
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• v.26 no.2
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• pp.23-32
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• 2010

This study was especially conducted to find out the characteristics of the lightweight air-mixed soil (slurry density 10 kN/$m^3$) containing silt related to water. Compression strength, permeability, and capillary height of the lightweight air-mixed soil were studied, and also to support these studies, the structure of that soil was analyzed in detail. Air bubbles of various sizes are inside the lightweight air-mixed soil, and its distribution in a location is almost constant. A numerous tiny pores are inside the air bubbles so that the lightweight air-mixed soil can be saturated with water. Porosity is also estimated through the image analysis. Peak strength of the lightweight air-mixed soil is not dependent on water, but behavior of stress-strain is affected by the water. Permeability is about $4.857{\times}10^{-6}cm/sec$, which is a little bit higher than the clay's permeability. Capillary rise occurs rapidly at the beginning of the test until the lapse of 100 minutes and then its increase rate becomes slow. The capillary rise causes the increase of the density of the lightweight air-mixed soil, and thus it is required to pay attention to this phenomenon during structure design and maintenance of the lightweight air-mixed soil.

• Proceedings of the Korea Association of Crystal Growth Conference
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• 1996.06a
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• pp.399-421
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• 1996

(1) The solute distribution mechanism was analyzed for the Si0.95Ge0.05 single crystal fiber by u-PD method. (2) The steady-state solutions were obtained for the molten zone and the capillary zone. (3) The effect of the convection in the molten zone on partitioning was not significant for many cases. (4) Intermediate transient rise of Ge was shown by the sudden change of the growth velocity or molten zone height. (5) Periodic compositional modulation can be designed by using the intermediate transient.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.57 no.3
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• pp.238-247
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• 2012

To determine the possibility of solidified se wage sludge for use as a soil cover material in reclaimed land, the growth of energy crops and soil chemical properties investigated in each experimental plots during 2 years (2010 and 2011). The experimental plots consisted of the mixing with solidified sewage sludge plot (SS50), the covering with solidified sewage sludge plot (SS100), and the original reclaimed land plot (ORL) on reclaimed land for the intended landfill in Sudokwon Landfill Site Management Corporation (SLC). Plant height, measured in the second year (2011), was highest in the Geodae 1 grown at plots treated with solidified sewage sludge. The growth of energy crops cultivated in both SS50 and SS100 were better than in ORL. The contents of organic matter (OM) and total nitrogen (T-N) at both SS50 and SS100 were considerably higher than that of the ORL over 2 years. However, the soil from ORL showed higher salinity with high contents of exchangeable $Na^+$ cation than that of SS50 and SS100 over 2 years. We consider that soil chemical and physical properties on reclaimed land used in this study could be improved by the application of solidified sewage sludge due to following reasons. Firstly, the application of solidified sewage sludge may provide soil nutrients on reclaimed land i.e. the growth of energy crops better than in ORL, resulted in more OM and T-N contents in SS50 and SS100. Secondly, the top layers mixed or covered with solidified sewage sludge on reclaimed land may be prevented the salinity accumulation due to capillary rise to surface soil, and improved the cultivation layer for effectively propagating the rhizomes of energy crops. Thus the solidified sewage sludge may be a great soil cover materials for cultivation of bioenergy crops in reclaimed land.