• Journal of the Korean GEO-environmental Society
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• v.1 no.1
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• pp.19-26
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• 2000

This study is and experimental study to investigate the possibility of the utilization of paper ash as the cover and liner materials in the waste disposal landfill and other construction materials. A series of tests were performed to evaluate basic properties, compaction, compressive strength, consolidation, permeability, and CBR of paper ash. The sample used in these tests was obtained from four paper mills which are located in near Ch$\hat{o}$ngju. Bentonite and lime were used as addictives to improve permeability properties of paper ash. It was found that the maximum dry unit weight increases with the increase of the bentonite and lime contents. The results of unconfined compression tests show that paper ash meets the criteria of the unconfined compression strength. It is recognized that the permeability coefficient decreases as increasing bentonite content and the percentage of bentonite needed to make the permeability coefficient below $1{\times}10^{-7}cm/sec$ was 30%.

• The Korean Journal of Physiology
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• v.28 no.2
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• pp.203-214
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• 1994

Using the methods of stopped-flow and epifluorescence microscopy with entrapped fluorophore, membrane permeability of $NH_3$ and weak acids in liposomes, renal brush border (BBMV) and basolateral membrane vesicles (BLMV), and primary culture cells from renal proximal tubule was measured. Permeability coefficient (cm/sec) of $NH_3$ was $(2.9{\times}10^{-2}$ in phosphatidylcholine liposome $25^{\circ}C)$, $5.9{\times}10^{-2}$ in renal proximal tubule cell $(37^{\circ}C)$, $4.0{\times}10^{-2}\;and\;2.4{\times}10^{-2}$ in BBMV and BLMV $(25^{\circ}C)$, respectively. Formic acid has the highest permeability coefficient among the weak acids tested, which was $4.9{\times}10^{-3}$ in liposome, $5.0{\times}10^{-3}$ in renal proximal tubule cell, $9.1{\times}10^{-3}$ in BBMV and $3.8{\times}10^{-3}$ in BLMV. There was a linear relationship between external concentration of nonionized formic acid and initial rate of flux of formic acid in liposome, and the slope coincided with the value of permeability coefficient of formic acid measured in pH 7.0. These results show that techniques of stopped-flow and epifluorescence microscopy with entrapped fluorophore provide the precise method of measurement of very rapid transport of nonelectrolytes through membranes with the advantages of instantaneous mixing effect, good resolution time and easy manipulation.

• Journal of the Korean Geotechnical Society
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• v.26 no.4
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• pp.15-26
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• 2010

To determine the frost heave suppressing mechanism of soil mixed with tire powder, we conducted three kinds of laboratory experiments: measurement of unfrozen water, evaluation of thermal conductivity, and a frost heave. In this research, we focused on changes in the coefficient of permeability of the mixed soil, and first found that of the unsaturated soil. Next, in the case of the presence of ice, we took the ice-impeding factor into consideration to derive the coefficient of permeability of the frozen fringe from the area ratio of the soil and tire powder in mixed soil. The results show a positive correlation between the water intake rate and the coefficient of permeability. Moreover, we found that the frost heave decreased thanks to a reduction in the permeability and a fall in the unfrozen water content of the soil mixed with tire powder. We also calculated the weight of the water content of the soil and tire powder void quantitatively using the result of the volumetric ratio of mixed soil.

• Journal of the Korean GEO-environmental Society
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• v.8 no.3
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• pp.35-40
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• 2007

The vertical drain method recently being used in Korea is divided into the sand drain method, the pack drain method, the paper drain method, and the PBD method according to the drainage. However, these methods generate the disturbed zone called the smear zone when the drainage is penetrated into the in-situ ground. The characteristics of the smear zone generated cause the problems that the coefficient of permeability decreases and the consolidation time becomes longer than expected in the design. Although the size of the smear zone is a very important factor directly influencing the degree of consolidation, in the existing studies, the general value for the size of the smear zone proposed has been used in the design. However, the size of the smear zone proposed by the existing studies cause a loss of economical efficiency because of the inaccuracy of the design. Hence, in this study, the characteristics on the size of the smear zone were analyzed by carrying out the three dimensional numerical analysis and the method to determine the conversion size of the smear zone considering the change of the coefficient of permeability was proposed in order to consider the change of the coefficient of permeability in the actual design.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2004.05a
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• pp.33-37
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• 2004

Recently, Growing tendency for structure surface to use water repellent agent has increased steadily. But investigation of it's protection and durability property is not sufficient. Therefore, this paper shows the investigation about repellent property and micro structure's change in surface layer of mortar that is applied by water repellent agent. Water repellent property, absorption coefficient, air permeability, porosity and observation of micro construct was investigated according to water repellent agent type. The test results indicated that mortar applied water repellent agent appears tiny absorption coefficient, but air permeability is maintained. The reason is because silane solution is coating at capillary surface of a wall and minute pore structure is changeless.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2002.05a
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• pp.31-36
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• 2002

Recently, more interests in surface treatment of structure with water repellent agent are steadily increased, But, investigation of its properties such as protection, durability, morphology of micro structure is not sufficient. Therefore, This paper is aimed for the investigation of water repellent property and change of morphology of micro pores in mortar that is treated by water repellent agent(Inorganic polymer based material). Water repellent property, water absorption coefficient, air permeability, porosity and the observation of micro structure was investigated in different water repellent agent type. The test results indicated that water repellent treated mortar showed low absorption coefficient and air permeability(breathing effect). This is why inorganic polymer is coated at the wall of capillary and micro pores, also, the volume of micro pore is reduced without the change of morphology in micro structure.

• Journal of the Korea Concrete Institute
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• v.12 no.5
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• pp.131-139
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• 2000

Porous Concrete usually contains large amount of voids(about 10∼20%) after compaction so that it has relatively high permeability. It has been introduced in domestic since early 1980's but it has problems such as lack of optimized mixture, low strength and durability, and other defects, etc. The purpose of this study is to manufacture high-performance porous concrete using polymer to enhance the mechanical properties. The results of this study are as follows; the compressive strength range 12 92∼207kgf/㎠, the tensile strength range is 14∼28kgf/㎠, the bending stength range is 42∼73kgf/㎠, and the coefficient permeability range is 5.77×10-2∼6.79×10-1cm/sec. To develope high-performance porous concrete. further studies are needed on optimum mixture of fineness modulus and admixture.

• Journal of The Korean Society of Agricultural Engineers
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• v.46 no.6
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• pp.13-19
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• 2004

This study was performed to evaluate permeable properties of eco-concrete using soil, natural coarse aggregate, soil compound and polypropylene fiber. The fIexural strength, ultrasonic pulse velocity and dynamic modulus of elasticity were increased with increasing the content of coarse aggregate, soil compound and polypropylene fiber. The flexural strength, ultrasonic pulse velocity and dynamic modulus of elasticity were 259 MPa, 3,527 m/s and 275 ${\times}$ 102 MPa at the curing age of 28 days, respectively. The coefficient of permeability was decreased with increasing the content of coarse aggregate and soil compound, but it was increased with increasing the content of polypropylene fiber. Accordingly, this concrete can be used for farm road.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.33 no.1
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• pp.64-72
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• 2001

The cigarette ventilation affects not only the amount of tar and nicotine delivery by a cigarette, but also the composition of the smoke. Therefore, it is important to stabilize of variability in cigarette ventilation that would be affected by changes in cigarette components. This work was conducted to determine the major factors that influence the cigarette ventilation and also to provide fundamental informations for improving the uniformity of cigarette performances. To evaluate the effect of cigarette ventilation as a dependant variable, the three independent factors were the air permeability of plugwrap, tipping paper and the filter pressure drop. We determined the effect of paper permeability on ventilation variability and the optimum condition in combinations of independent factors. The mean of cigarette ventilation was increased as plugwrap permeability increases, particularly at 26,000 CU. However, it was exhibited that standard deviation and coefficient of variation of the cigarette ventilation were decreased with increasing plugwrap permeability. At the 600 CU and 1,200 CU of tipping paper permeability, process capability index (Cp) of the cigarette ventilation increased as plugwrap permeability increases. Following the optimum condition of cigarette ventilation induced by fitted regression equation, one was to optimize 50% ventilation level is by combination with plugwrap permeability of 16,000 CU, tipping paper permeability of 810 CU, filter pressure drop of 319 mm$H_2O$, respectively.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.10a
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• pp.545-552
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• 2002

The purpose of this paper is to investigate permeability characteristic of soil-bentonite landfill liner and development of desirable liner system. In this study, permeability tests for soil-bentonite, reactive soil-bentonite and apply bentomat and reactive mat are carried out under the low and high water pressure. According to test result, additional amount of bentonite decreases the coefficient of permeability up to the bentonite mixture ratio of 15%. Therefore, the permeability test for landfill liner's indicated that the use of general water would be in more safe side because the liner system show low permeability duet decrease effect of porous by suspended soild(SS). The permeability of leachate for Zeolite mixture ratio 0, 5, 10% with bentonite mixture ratio 15% showed negligible variation in the permeability with general water. Therefore, Zeolite could be used as a successful that is available purification material for the treatment of leachate, without changing the of landfill liners. Also odious smell could be removed by adding smell amount of Zeolite to the leachate. It was revealed that the bentomat and reactive mat installed in soil-bentonite layer effectively improved the permeability as well as purification of the leachate.