• 한국세라믹학회지
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• 제30권3호
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• pp.169-174
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• 1993

The porous silica glass prepared by the sol-gel method from the mixed solution of Si(OCH3)4, H2O, HCl and CH3OH with HCONH2 as a DCCA (Drying Control Chemical Additives). For investigation the characteristics of gels and glasses, we examined gels and glasses using TG-DTA, XRD, IR, SEM and porosimeter. The more content of formamide in the mixed solution increased, the more pore size and porosity of gel increased. In the excess formamide added gel, the properties of pore of gel were not so changed. The porous silica glass was prepared from the dry gel after heat treatment at 75$0^{\circ}C$. Porosity and mean pore size of the porous silica glass was 17~25% and 40~60$\AA$ relatively.

• 펄프종이기술
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• 제47권5호
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• pp.104-111
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• 2015

Factors influencing penetration of PVAm solution into paper during impregnation were investigated with ultrasonic Penetration Evenness Analyzer (PEA). Paper structure was varied by changing basis weight, freeness of pulp, calendering, and filler addition, and hydrophobicity of paper was varied by adding AKD. In addition, the viscosity of PVAm solution was varied by changing the concentration of PVAm solution. Important factors influencing penetration of PVAm solution into paper were found to be the pore structure and the hydrophobicity of paper, and the viscosity of PVAm solution. Pore structure of paper could be controlled by refining degree and filler addition and hydrophobicity of paper could be controlled by internal sizing. Denser structure of paper, higher hydrophobicity and higher liquid viscosity slowed down the penetration of PVAm solution into paper.

• 멤브레인
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• 제17권4호
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• pp.329-337
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• 2007

본 연구에서는 p-toluenesulfonic acid (TSA)와 polyvinylpyrrolidone (PVP)를 함유한 polyethersulfone (PES) 고분자 용액을 이용하여 PES 멤브레인 내에 최소 공경을 갖는 내부 분리층을 만드는 방법에 관한 새로운 방법을 제시하고자 한다. 팽윤제로 사용된 PVP와 응고제로 사용된 TSA를 함유한 평막형 PES 멤브레인의 제조 및 구조적인 특성 조사가 수행되었으며, 상업용 막에 대등할 만한 투과 성능과 좁은 pore size distribution을 가지는 멤브레인을 제조할 수 있음을 확인하였다. 또한 PVP의 첨가는 멤브레인의 단면구조와 투과 성능에, TSA는 투과 성능보다는 pore size distribution에 영향을 준다는 것을 확인하였으며 이는 FE-SEM 결과와 TSA를 첨가한 멤브레인의 단면 사진에서 내부 최소 기공층의 두께가 두꺼워짐을 확인할 수 있었다.

• 공업화학
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• 제7권2호
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• pp.393-400
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• 1996

Seed 유화 중합법과 용매 추출법을 이용하여 전도성 고분자 복합체를 위한 다공성 입자를 제조하였다. 건조된 다공성 입자를 모체 고분자로 사용하여 dopant로 사용하는 $FeCl_3$를 methanol에 녹여 흡수시킨 뒤에 건조시키고, 이를 다시 pyrrole를 녹인 ethyl ether 용액으로 중합하여 용액을 증발시킴으로서 전도성 고분자 복합체를 합성하였다. 이때, 모체 고분자로 사용된 비다공성 입자와 다공성 입자의 전도도를 비교하였다. 실험결과, 전도성 복합체의 전도도는 비다공성 입자보다는 다공성 입자를 사용하여 제조한 복합체가 전도성 중합체가 입자의 표면뿐만 아니라 pore안에서도 용이하게 형성되어 더 우수한 전도도를 나타내었다.

• The Korean Journal of Physiology and Pharmacology
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• 제8권5호
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• pp.259-264
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• 2004

Cytolysin produced by Vibrio vulnificus has been incriminated as one of the important virulence determinants in V. vulnificus infection. Ion selectivity of cytolysin-induced pores was examined in a CPAE cell, a cell line of pulmonary endothelial cell, using inside-out patch clamp techniques. In symmetrical NaCl concentration (140 mM), intracellular or extracellular application of cytolysin formed ion-permeable pores with a single channel conductance of $37.5{\pm}4.0$ pS. The pore currents were consistently maintained after washout of cytolysin. Replacement of $Na^+$ in bath solution with monovalent ions $(K^+,\;Cs^+\;or\;TEA^+)$ or with divalent ions $(Mg^{2+},\;Ca^{2+})$ did not affect the pore currents. When the NaCl concentration in bath solution was lowered from 140 to 60 and 20 mM, the reversal potential shifted from 0 to -11.8 and -28.2 mV, respectively. The relative permeability of the cytolysin pores to anions measured at $-40\;mV\;was\;Cl^-\;=\;NO_2^-\;{\geq}\;Br^-\;=\;I^-\;> \;SCN^-\;>\;acetate^-\;>\;isethionate^-\;>\;ascorbic acid^-\;>\;EDTA^{2-},$ in descending order. The cytolysin-induced pore current was blocked by $CI^-$ channel blockers or nucleotides. These results indicate that V. vulnificus cytolysin forms anion-selective pores in CPAE cells.

• Geomechanics and Engineering
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• 제35권4호
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• pp.385-393
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• 2023

To analyze the consolidation with horizontal sand drains, the plane strain consolidation model under multi-ramp loading is established, and its corresponding analytical solution is derived by using the separation of variables method. The proposed solution is verified by the field measurement data and finite element results. Then, the effects of the loading mode and stress distribution on consolidation and dissipation of pore pressure are investigated. At the same time, the influence of hydraulic conductivity and thickness of sand blankets on soil consolidation are also analyzed. The results show that the loading mode has a significant effect on both the soil consolidation rate and generation-dissipation process of pore water pressure. In contrast, the influence of stress distribution on pore pressure dissipation is obvious, while its influence on soil consolidation rate is negligible. To guarantee the fully drained condition of the sand blanket, the ratio of hydraulic conductivity of the sand blanket to that of clay layer k_d/k_v should range from 1.0×10⁴ to 1.0×10⁶ with soil width varying from 100 m to 1000 m. A larger soil width correspondingly needs a greater value of kd/kv to make sure that the pore water can flow through the sand blanket smoothly with little resistance. When the soil width is relatively small (e.g., less than 100 m), the effect of thickness of the sand blanket on soil consolidation is insignificant. And its influence appears obvious gradually with the increase of the soil width.

• 유기물자원화
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• 제12권2호
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• pp.82-90
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• 2004

본 연구에서는 PAHs 중에서 흔히 높은 농도로 발견되고 있는 나프탈렌 오염토양에 대하여 지중토양세정으로 세정한 후 세정된 용액을 고분자 응집제로 처리하였다. 오염물질로는 2-methylnaphtalene과 1,5-dimethylnaphtalene을 사용하였다. 세정용액으로는 POE12와 SDS를 1 : 1 (부피비)로 혼합한 계면활성제를 사용하였다. 혼합계면활성제의 주입횟수를 5 pore volume까지 증가시켰을 때 2-methylnaphtalene의 세정효율은 지수적으로 1,5-dimethylnaphtalene의 제거율은 다소 선형적으로 증가하여 각각 약 80%와 60%가 세정되었다. 13 pore volume으로 세정한 후 2-methylnaphtalene과 1,5-dimethylnaphtalene의 세정효율은 각각 약 90%와 82%로 2-methylnaphtalene이 1,5-dimethylnaphtalene 보다 다소 높았으나, 물에 의하여 세정된 부분을 보정하면 약 42%와 71%로 상대적으로 소수성인 1,5-dimethylnaphtalene의 세정효율이 더 높았다. 약 10,000 mg/kg(건조토양)의 디젤 TPH는 5 pore volume의 주입에서 약 40%의 세정효율만을 나타내었으며, 추가적으로 13 pore volume까지 첨가하였을 때 약 70%의 세정효율을 보였다. 그러나 디젤내 나프탈렌 성분은 세정용액을 4 pore volume 까지 주입하였을 때까지 세정효율이 급격히 증가하였으며, 5 pore volume을 가하였을 때 90%가 세정되어 디젤 TPH의 40%보다 두 배 이상 높은 세정효율을 나타내었다. 2-Methylnaphthalene과 1,5-dimethylnaphthalene 오염토양 용출세정액은 6가지 고분자 응집제로 처리한 결과 응집제 모두 50% 부근의 비슷한 제거율을 나타내었다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 총회 및 춘계학술발표회
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• pp.418-421
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• 2003

Surfactant enhanced in-situ soil flushing was peformed to remediate the soil and groundwater at an oil contaminated site, and the effluent solution was treated by the chemical treatment process including DAF(Dissolved Air Flotation). A section from the contaminated site(4.5m$\times$4.5m$\times$6.0m) was selected for the research, which was composed of heterogeneous sandy and silt-sandy soils with average Hydraulic conductivity of 2.0$\times$10$^{-4}$ cm/sec. Two percent of sorbitan monooleate(POE 20) and 0.07% of iso-prophyl alcohol were mixed for the surfactant solution and 3 pore volumes of surfactant solution were injected to remove oil from the contaminant section. Four injection wells and two extraction wells were built in the section to flush surfactant solution. Water samples taken from extraction wells and the storage tank were analyzed by GC(gas-chromatography) for TPH concentration with different time. Five pore volumes of solution were extracted while TPH concentration in soil and groundwater at the section were below the Waste Water Discharge Limit(WWDL). Total 18.5kg of oil (TPH) was removed from the section. The concentration of heavy metals in the effluent solution also increased with the increase of TPH concentration, suggesting that the surfactant enhanced in-situ flushing be available to remove not only oil but heavy metals from contaminated sites. Results suggest that in-situ soil flushing and chemical treatment process including DAF could be a successful process to remediate contaminated sites distributed in Korea.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2003년도 춘계학술발표강연 및 논문개요집
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• pp.53-53
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• 2003

There has been increasing interest in the fabrication of nano-sized structures because of their various advantages and applications. Anodic Aluminum Oxide (AAO) is one of the most successful methods to obtain highly ordered nano pores and channels. Also It can be obtained diverse pore diameter, density and depth through the control of anodization condition. The three types of substrates were used for anodization; sheets of Aluminum on Si wafer and Aluminum on Mo-coated Si wafer. In Aluminum sheet, a highly ordered array of nanoholes was formed by the two step anodization in 0.3M oxalic acid solutions at 10$^{\circ}C$ After the anodization, the remained aluminum was removed in a saturated HgCl$_2$ solution. Subsequently, the barrier layer at the pore bottom was opened by chemical etching in phosphoric acid. Finally, we can obtain the through-channel membrane. In these processes, the effect of various parameters such as anodizing voltage, anodizing time, pore widening time and pre-heat treatment are characterized by FE-SEM (HITACH-4700). The pore size. density and growth rate of membrane are depended on the anodizing voltage and temperature respectively. The pore size is proportional to applied voltage and pore widening time The pore density can be controlled by anodizing temperature and voltage.

• Coupled systems mechanics
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• 제6권4호
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• pp.487-499
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• 2017

This paper investigates the approximate solution bounds of radon diffusion equation in soil pore matrix coupled with uncertainty. These problems have been modeled by few researchers by considering the parameters as crisp, which may not give the correct essence of the uncertainty. Here, the interval uncertainties are handled by parametric form and solution of the relevant uncertain diffusion equation is found by using Galerkin's Method. The shape functions are taken as the linear combination of orthogonal polynomials which are generated based on the parametric form of the interval uncertainty. Uncertain bounds are computed and results are compared in special cases viz. with the crisp solution.