• 한국방재학회:학술대회논문집
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• 2007.02a
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• pp.546-550
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• 2007

High excess pore water pressure may develop when loose saturated sand is subjected to earthquake excitation, resulting in reduction in the shear strength and stiffness, and ultimately can result in liquefaction. It is very important to accurately assess the level of the pore pressure generation for seismic design and to perform effective stress analysis. A simple numerical 모형 is developed for estimating the development of pore water pressure due to seismic loading. The method only uses two parameters and the length of the accumulated shear strain. The accuracy of the proposed 모형 is verified through a series of laboratory test data. Comparisons show that the modified 모형 is an improvement over existing 모형s.

• Journal of the Korean Ceramic Society
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• v.45 no.12
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• pp.845-850
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• 2008

Hydrated sodium silicate was synthesized by hydrothermal reaction using anhydrous sodium silicate. The optimum additions of water was 25wt% to make hydrated sodium silicate with homogeneous and purposed water contents. Porous ceramics with homogeneous microstructure and spherical closed pore can be fabricated by elimination of the large pores(a few mm in size) which was formed during first heat treatment through the decomposition of water. Spherical closed pore was formed above $600^{\circ}C$ and the pore size was increased with increasing second heat treatment temperature due to growth of pores. The size of spherical closed pore was varied from 35 to $233\;{\mu}m$ and specific gravity was varied from 0.2 to 1.02 depending on the combinations of the first and second heat treatment temperature.

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.150-153
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• 2009

Anion exchange polymer electrolyte pore-filling membranes consisting of the whole hydrocarbon materials were prepared by photo polymerization with various quaternary ammonium cationic monomers and characterized on the properties for applying to solid alkali fuel cell (SAFC). Hydrocarbon porous substrates such as polyethylene were used for the preparation of the pore-filling membranes. The hydroxyl ion conductivity of the polymer electrolyte membranes prepared in this research was dependent on the composition ratio of an electrolyte monomer and crosslinking agents used for polymerization. Furthermore, these pore-filling membranes have commonly excellent properties such as smaller dimensional affects when swollen in solvents, higher mechanical strength, lower fuel crossover through the membranes, and easier preparation process than those of traditional cast membranes.

• Journal of the Korean institute of surface engineering
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• v.24 no.3
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• pp.162-168
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• 1991

Gas diffusion and electrolyte penetration in wetproofed gas diffusion electrodes were studied using layers of PTFE- bonded carbon. Minor variations in fabrication and testing procedures resulted in very large variations in catalyst layer wetting characteristics and permiability for reaction gas. By controlling the pore size of gas diffusion electrode carefully by varing the PTFE contents, baking temperature, baking time and ammonium bicarbonate as additive, the primary pore was decreased and the secondary pore was increased and so more reaction gas through the primary pore could be reacted at catalyst agglomertes in the secondary pore. And the cathode current density was increased to more than 400mA.$\textrm{cm}^2$ and Tafel slope value was decreased to lower than 110mA/decade.

• Journal of the Korean Society of Clothing and Textiles
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• v.26 no.7
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• pp.1078-1084
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• 2002

Cotton fabrics were treated with 1,2,3,4-butanetetracarboxylic acid(BTCA) to impart durable press performance, which is formaldehyde-free DP finishing reagent. The pore structures of BTCA treated cottons were compared using a reverse gel permeation chromatographic technique(reverse GPC). A series consisting 4 kinds of water soluble sugars was used to study the elution characteristics of columns prepared from cotton fibers. From these data, differences in pore size distribution in the control and BTCA treated cottons were distinguished. BTCA crosslinks cellulose molecules provided wrinkle resistance to the treated cotton fabrics through ester linkages. Although crosslinking of cotton with BTCA reduced accessible internal volume across the entire range of pore size, differences in line pores were larger than in small pores. BTCA treated cotton exhibited reductions over 40% in large pore sizes.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.14 no.2
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• pp.128-135
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• 2002

An existing numerical model fo r determining the wave field and pore pressures inside rubble mound breakwater was reformulated here especially to enhance the predictability of interior pore pressures. The pore pressures strongly depend on the nonlinear wave field occurring along frontal slope which is very difficult to be numerically reproduced. In the present study, hence, the amplitude and phase informations of wave pressures along the frontal slope are obtained directly through a hydraulic model test and are incorporated into the numerical model. The interior wave field is analyzed by a boundary element method, and thereby the pore pressures are determined. It was found that the calculated pore pressures agreed quite well with experimental values.

• Membrane and Water Treatment
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• v.15 no.1
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• pp.31-39
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• 2024

The flow in a nanopore of filtration membrane is often multiscale and consists of both the adsorbed layer flow and the intermediate continuum fluid flow. There is a controversy on which interface the slippage should occur in the nanopore filtration: On the adsorbed layer-pore wall interface or on the adsorbed layer-continuum fluid interface? What is the difference between these two slippage effects? We address these subjects in the present study by using the multiscale flow equations incorporating the slippage on different interfaces. Based on the limiting shear strength model for the slippage, it was found from the calculation results that for the hydrophobic pore wall the slippage surely occurs on the adsorbed layer-pore wall interface, however for the hydrophilic pore wall, the slippage can occur on either of the two interfaces, dependent on the competition between the interfacial shear strength on the adsorbed layer-pore wall interface and that on the adsorbed layer-continuum fluid interface. Since the slippage on the adsorbed layer-pore wall interface can be designed while that on the adsorbed layer-continuum fluid interface can not, the former slippage can result in the flux through the nanopore much higher than the latter slippage by designing a highly hydrophobic pore wall surface. The obtained results are of significant interest to the design and application of the interfacial slippage in nanoporous filtration membranes for both improving the flux and conserving the energy cost.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1997.04a
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• pp.53-61
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• 1997

The effect of sintering condition on tribological behavior in the Cu-base sintered friction materials was studied through pin-on-disk type wear tester. Especially, the experiment was focused on making a comparative study between presstwed sintering and pressureless sintering. Pressureless sintering process showes more stable friction coefficient and lower wear rate than pressure sintering process. This result is related to pore size and density of pore in the sintered materials.

• Journal of the Korean Geotechnical Society
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• v.30 no.7
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• pp.27-40
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• 2014

So far, studies on the settlement of breakwater have mainly been conducted through numerical model tests focusing on an analysis or through the laboratory wave tank tests using a scaled model. There has not been a study on the settlement that is measured in an actual breakwater structure. This study analyzed the data of settlement that has been measured in an actual caisson breakwater for a long time and the characteristics and causes of wave-induced settlement in the caisson (including beneath ground), based on qualitative aspect, were examined. The analysis revealed that wave clearly has an effect on the settlement in caisson, especially in the condition of high wave such as typhoon. Caisson settlement is caused by the liquefaction of ground, which is due to the increase of excess pore pressure, the combination of oscillatory excess pore pressure and residual excess pore water pressure, and the solidification process of ground due to dissipation of the accumulated excess pore pressure. The behavior of excess pore pressure in the ground beneath the caisson is entirely governed by the behavior of the caisson. Ground that has gone through solidification is not likely to go through liquefaction in a similar or a smaller wave condition and consequently, the possibility of settlement is reduced.

• Proceedings of the Korea Concrete Institute Conference
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• 1991.10a
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• pp.11-14
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• 1991

Apparent diffusion coefficients of Cl-ions through hardened cement paste(HCP), which were partly substituted blending materials, were determined. Also, pore solution was extracted from HCP which were immersed in NaCl solution, and Cl- concentration of the solution were analyzed. Partly substitution of pozzolanic materials considerably reduced the diffusion rate for Cl-ions and Cl- concentration of pore solution. Binding capacity of Cl- is related to the content of Al2O3 and pozzolanic reactivity.